Charles W Lynde MD, FRCPC¹, James Bergman MD, FRCPC², Loretta Fiorillo MD³, Lyn Guenther MD, FRCPC⁴, Marissa Joseph MD, FRCPC, FAAD⁵, Jill Keddy-Grant MD⁶, Ian Landells MD, FRCPC⁷, Danielle Marcoux MD, FRCPC⁸, Catherine McCuaig MD, FRCPC⁹, Michele Ramien MD¹⁰, Wingfield Rehmus MD MPH FAAD¹¹

Introduction

Atopic dermatitis (AD) is a lifelong pruritic, inflammatory skin disease associated with altered immune function and epidermal barrier dysfunction.^1-3 The chronic and recurring cyclic waxing and waning nature of AD leads the patient to treatment fatigue and imposes a significant burden on both the patients’ and caregivers’ quality of life (QoL).¹ AD frequently appears early in childhood and affects over 20% of children and up to 3.5% of adults.^2,3 Measurements of the prevalence of AD can differ, and this variability can be impacted by geographic location, population studied, and definition of AD used. A Canadian study showed that the adult prevalence of AD is up to 3.5% and that AD may be more prevalent among First Nations populations.² This research further revealed that men were less affected than women and that AD decreases with age. Additionally, the study noted that the severity of AD varies per region.² In many countries, the prevalence of AD is on the rise, especially in young children from developing lower-income countries in South East Asia and Latin America.⁴ Although the role of race and ethnicity in the pathophysiology of AD remains unclear, a higher incidence of AD was observed in Black American children (17.3%) compared to White children (10.4%).⁴

The pathophysiology includes skin barrier defects, inflammatory cytokines, and immune abnormalities. ADs’ etiology is multifactorial and involves an incompletely understood interaction between genetic factors, immune system dysfunction, skin barrier disorders, genetic and environmental stressors.^5,6 Most of the patients with AD have mild disease; however, 10% – 20% of children with AD are categorized as severe, and these rates are slightly higher in adults.²

There is a need for a variety of therapeutics targeted to different levels of severity.^6,7 A treatment paradigm that recognizes that patients may oscillate between degrees of severity and integrates topical and systemic therapies may align more closely with clinical reality.^8,9 AD treatment is often challenging due to the disease itself, treatment fatigue, and patient/caregiver concerns. Patients and caregivers frequently have concerns about medication safety and adverse events (AEs) as well as the long-term use of topical corticosteroids (TCS) or topical calcineurin inhibitors (TCI).⁹ Crisaborole ointment is an effective and safe alternative to TCS and TCI.⁹ Sharing best clinical practice standards, addressing challenges in treatment application, and methods to improve patient adherence to therapy may improve treatment results.⁹

This paper aims to review best clinical practices in treating AD patients, explore optimal use of crisaborole in mild to moderate disease, and provide expert guidance for the real-world use of crisaborole ointment to improve patient outcomes. This papers’ target audience is general practitioners, pediatricians, pediatric dermatologists, and dermatologists who treat patients with AD.

Methods

The project used a modified Delphi communication technique for interactive decision-making for medical projects, adapted from face-to-face meetings to suit a virtual platform.^10-12 The meeting was virtually convened on May 8, 2021, and the expert panel consisted of eleven dermatologists, including nine pediatric dermatologists from diverse geographical regions within Canada, who commonly treat patients with AD. In preparation for the meeting, a literature review surrounding crisaborole for the treatment of mild-moderate AD was conducted, and the panel members were surveyed regarding the use of crisaborole ointment for the treatment of AD.

The literature review and the pre-meeting survey results were presented at the virtual meeting. During the meeting, the experts were divided into three breakout groups to discuss and adopt draft recommendations for the real-world use of crisaborole ointment that were prepared from the literature searches by CWL and AA. The three groups presented their adapted versions of the recommendations to the larger group following the breakout session. The adapted recommendations were then collated and edited if necessary. The panel then voted and adopted the recommendations using evidence coupled with expert opinion based on the clinical experience of the advisors. The meeting summary and subsequent review of the manuscript were performed online (Figure 1).

Literature Review

Searches for English-language literature [2015– 2020] took place on April 14, 2021, on PubMed and Google Scholar as a secondary source. The data gathered by the literature review prioritized clinical studies published on the use of crisaborole, articles describing the current best practice in AD, and the most recent clinical guidelines, consensus papers and, algorithms. Excluded were duplications, articles of insufficient quality [small sample size, flawed methodology], and the most recent reviews were used in the case of review articles.

The searches yielded sixty-two papers deemed clinically relevant to current best practices of crisaborole use in AD. After removing duplicates and articles of insufficient quality, thirty publications remained: Four on epidemiology, ten reviews, three consensus papers and algorithms, four guidelines, five clinical studies, and four systematic reviews, meta-analyses, or posthoc analyses.

Results

The literature review indicated that the guidelines, algorithms, and consensus papers for topical AD treatment had not changed significantly over the past decade apart from adding crisaborole ointment and removing the black box for topical calcineurin inhibitor (TCI) treatment.^{7-9, 13-21}

A consensus paper and algorithm that explored the need for practical solutions to improve AD care was developed and published by the authors’ panel.⁸ The consensus statements and algorithm for topical treatment and maintenance of AD were integrated into the panels’ recommendations presented in this publication.

The DERMA (D: Diagnosis/Distribution; E: Education/Emollients; R: Red/Itchy; M: Medication/Maintenance; A: Assessment /Adherence) AD Algorithm targets a broad base of health care professionals treating patients with AD. The consensus statements and DERMA AD algorithm for topical treatment and maintenance of AD reflected current practice and were integrated into the panels’ recommendations (Figure 2).

Clinical Evidence of Crisaborole

Crisaborole is a small molecule, anti-inflammatory nonsteroidal PDE4-I inhibitor for the treatment of AD, which has demonstrated safety and efficacy in patients with mild-to-moderate AD.^22-30 Two percent crisaborole ointment was first approved by the American Food and Drug Administration (FDA) in December 2016 and then in 2018 by Health Canada for mild-to-moderate AD patients aged 2 years and over and in March 2020 (USA) and May 2021 (Canada) for patients aged 3 months and over.²⁵

The efficacy and safety studies on crisaborole used various clinical assessment scales such as Investigator Static Global Assessment (ISGA), Atopic Dermatitis Severity Index (ADSI), Eczema Area, and Severity Index (EASI) score, and Patient-Oriented Eczema Measure (POEM).

A randomized, double-blind, intra-patient controlled study (for the first 14 days) was continued as an open-label study applying crisaborole to all lesions. The study, including 40 patients of 18 years-old and older, demonstrated significant changes from baseline in crisaborole-treated lesions, ISGA, and pruritus NRS improvement from day fifteen assessment onwards.²³ The study also showed normalization of the genomic skin profile (approximated normal skin), inhibition of inflammatory genes known to be induced through degradation of cAMP by PDE4, and reduction in epidermal hyperplasia and TEWL.²³

The safety and efficacy of crisaborole treatment over 28 days were shown in two identical randomized, double-blind, vehicle-controlled studies including 1,522 patients with mild-to-moderate AD of 2 years and over.²² Significantly more patients treated with crisaborole than vehicle reached the primary endpoint (ISGA: clear, almost clear) than those treated with the vehicle at day 29 assessment.²² A long-term, open-label, single-arm 48 weeks safety study that included 517 patients of 2 years and over showed similar safety results as in a previous study that included adult AD patients.^22,24 In the long-term open-label study, nine patients (1.7%) withdrew due to AEs such as a stinging sensation after applying the ointment.²⁴ Another phase four open-label, single-arm study on 137 infants aged 3 months to less than 24 months of age demonstrated that crisaborole is safe and effective. ISGA of clear or almost clear was achieved at day 29 assessment by 30.2% of patients.²⁵ The study further indicated that improvements exceeded the minimal clinically significant difference in total POEM score at day eight and day twenty-nine.²⁵ The POEM subscale data further revealed improved sleep and pruritus, markedly improving patients’ and their caregivers’ quality of life.²⁵ Crisaborole yielded a rapid and statistically significant reduction in pruritus within four days.^26-28 Notably, in two vehicle-controlled studies, the vehicle effect on pruritus was considerable.^26,28

A pooled analysis of four studies of mild-to-moderate AD patients demonstrated efficacy and local tolerability of crisaborole treatment. After crisaborole use, most patients had mild to no pruritus from the first assessment through the remainder of treatment.²⁷

In a further study, treatment with crisaborole resulted in a marked improvement in QoL for patients and their parents, caregivers, and families.²⁸

A post hoc analysis of 2 phase 3 studies showed the effectiveness of crisaborole compared to the vehicle in significantly alleviating mild-to-moderate AD severity (per ADSI), and percentage of body surface area (%BSA) affected.²⁹

Finally, a systematic literature review and network meta-analysis comparing efficacy and safety profiles of crisaborole ointment, 2%, versus other topical treatments for mild-to-moderate AD showed crisaborole was superior to vehicle and pimecrolimus 1% cream, and comparable to tacrolimus, 0.1% or 0.03% ointments, concerning ISGA 0/1 at 28-42 days.³⁰ Additionally, the systematic review showed that the AEs rates for application site burning/stinging were much higher for TCIs than for crisaborole.³⁰ The studies included different patients, and endpoints varied, so comparative assessment of medications from this meta-analysis is difficult. Head to head comparative studies are needed to see objective scientifically-grounded efficacy comparison.

Crisaborole works better for mild than moderate disease, where it provides a faster reduction of pruritus and other AD symptoms relieve.^9,25-30 Crisaborole is not typically used with TCI due to potential irritation, but the combination may be suitable for steroid-phobic patients and those at high risk of sequelae.⁹

It is advisable to avoid crisaborole application on significantly flared skin due to possible irritation. Crisaborole ointment can be beneficial for dermatitis of the hands and feet due to the potential for deeper penetration into inflamed, thicker lichenified skin as a result of the smaller molecular size of crisaborole. There appears to be less irritation of the hands and feet, and the good safety profile of crisaborole justifies application in infants and children.^9,25-30

Statements and Recommendations

Statement 1: Atopic dermatitis (AD) is a lifelong inflammatory skin condition associated with epidermal barrier dysfunction and altered immune function. When AD is not controlled by behavioral measures such as skincare and avoidance of triggers, treatments such as TCS, TCI, and more recently, PDE4-I should be considered. It is important to use topical agents in conjunction with moisturizers and gentle cleansers.

The complex multifactorial pathogenesis of AD includes genetic and environmental factors.⁵ The skin barrier in AD is dysfunctional, and this defective skin barrier leads to water loss from the skin and the ingress of irritants, pathogens and allergens resulting in further inflammation.⁷ As the dysfunctional barrier at baseline is further disrupted, an inflammatory immune response is upregulated, which further disrupts the barrier leading to a feedback loop.^6,31,5,6

AD presents clinically as recurrent scaly erythematous and pruritic papules and plaques of skin with varying severity. This morphology, in addition to pruritus and family history of atopy, are important diagnostic criteria.^7,32 Specific signs of AD include oozing, scaling, crusting, erythema, edema, and lichenification, which, together with the body surface area involved and the impairment of daily activities, help determine AD severity (Figure 3-5).
Most patients with AD present with mild disease and can be adequately treated with frequent moisturization and topical therapy such as TCS, TCI, or crisaborole.^{3,5,7,8,12-21}

Educating patients and caregivers about the condition, avoiding triggers, and daily skincare regime, including gentle cleansers and moisturizers, is a vital part of the approach.^{7-9, 13-21}

AD is a chronic disease, and as a result, adherence to therapy is a major obstacle. Education and patient support and can improve adherence and, in turn, outcomes. It is important to remember that AD education is not a one-and-done phenomenon. Ongoing reinforcement of the treatment plan and goals is needed. Clinicians need to explain the condition, the rationale for treatment, optimal treatment use, and demonstrate the application process in their office.^8,9 During the detailed conversation, solicit the patients’ or caregivers’ input and questions to enable their active role in the process.⁹ This will help manage expectations, adherence to treatment, and maintenance of the lifelong chronic disease.⁹ Actions to improve patient adherence with treatment include detailed but easy to follow information and options to revisit the information by reading materials or trusted websites (Box 1).^8,9,15,19

Box 1: Patient and caregivers information and education about crisaborole

Statement 2: Crisaborole, 1% ointment, is a nonsteroidal anti-inflammatory PDE4-I with demonstrated efficacy in patients aged three months and older with mild to moderate AD. It is a well-tolerated alternative to TCS or TCI and can be used on any body site. It may be especially beneficial for:

• Sensitive areas prone to thinning from TCS such as the face, intertriginous areas, and genitals
• Hand, feet, palms, and soles, where the small molecular size may allow potential deeper penetration

A previous publication by the panel reviewed various cases that reflect real-world clinical use of crisaborole aimed to clarify its optimal use as monotherapy, combination therapy, sequential therapy, and maintenance therapy.⁹ Crisaborole can provide a good and safe alternative to TCS and TCI, such as in cases of steroid or TCI avoidance, and can be used in mild-to-moderate AD patients from 3 months of age upwards.²⁵

The case studies discussed in the article suggested that crisaborole treatment was effective and well-tolerated for pediatric AD of the face, hands, and feet of infants, toddlers, young children, and adults where therapy with TCS or TCI had failed.⁹ One of the cases was a 5-year-old boy with moderate-to-severe AD of his hands that was painful and severely impacting daily activities, such as playing and interacting with other children. After eight weeks of crisaborole use, his hand palms and wrists involvement had almost entirely cleared.⁹

The advisors recommend that the smaller molecular size of crisaborole may allow better penetration into the skin to the site of inflammation.⁹ The advisors also indicated that there might be a cumulative effect of adding crisaborole for hands and feet that can benefit from its optimal penetration as part of a combination regimen with TCS and TCI in moderate-to-severe AD cases.⁹

Statement 3: Crisaborole may be used as a first-line topical agent and is also a good choice when previous treatment has yielded suboptimal results when TCS side effects constitute a significant concern, and in the case of TCS/TCI phobia.

TCS and TCI hesitancy exists among all cultures and likely contribute to AD treatment failure.³³ Widely available biased unreliable, and inaccurate sources of information about eczema and topical therapies such as TCS and TCI are not helpful for AD patients and hinder physicians ability to educate and treat appropriately.³³ Clinicians must inquire about and if present must thoroughly discuss the patients and caregivers’ concerns about TCS and TCI and emphasize that these treatments are vital and, if used appropriately, safe and effective.^{5,7,8,9,12-21} Providing the patient with trusted websites can give balanced information, thus addressing the issues that are adding to patients concerns, especially in those with TCS and TCI phobia.^15,19

If patients or caregivers continue to have safety concerns surrounding TCS/TCI treatment, then crisaborole can offer a safe alternative even in infants as young as three months of age.²⁵ In this situation, offering a safe and effective alternative to TCS or TCI may improve treatment adherence and patient outcomes.⁹

Statement 4: When starting topical therapies such as crisaborole, consider the following:

• Test the patients’ tolerability with a sample before a prescription to determine the degree of stinging
• Avoid its initial use on severely inflamed or open areas of skin
• Limit its use to areas less likely to sting/burn
• Use the product in combination with a refrigerated moisturizer

The recommendations are supported by the advisors’ clinical experience⁹, a post hoc analysis of 2 phase 3 studies²⁹, and a systematic literature review comparing efficacy and safety profiles of crisaborole and other topical treatments in mild-to-moderate AD.³⁰ Crisaborole is used in mild-to-moderate AD, but it is best to avoid application on severely inflamed and open areas if possible to minimize stinging.^29,30

Testing the patients’ tolerability in-office before prescribing crisaborole provides an opportunity to teach the patient about the appropriate application of the medication and identifies the uncommon patient who has more prominent stinging and thus may not tolerate the medication. The application also helps to identify the patient who has mild discomfort. Proper education and guidance can minimize the symptoms and allow then to get past the short-term symptom. Application in the office and identifying these subgroups will instill greater confidence in the medication and make it more likely that the prescription will be filled and utilized rather than abandoned after one application.

Improved knowledge about the central roles a defective skin barrier and dry skin may play in AD increasingly recognizes the benefits of daily and ongoing use of mild cleansers and moisturizers.³⁴ The use of a gentle cleanser that employs advanced vehicles with a near-physiologic pH (4.0–6.0) may help maintain skin barrier function by optimizing skin surface pH levels.³⁴ Utilizing moisturizers to optimize the barrier decreases water loss, decreases inflammation, and improves the skin’s barrier and natural moisturizing factors. Moisturizers that contain skin lipids such as ceramides have shown benefits over standard emollients when used for AD patients.³⁵

In an algorithm for South and East Asian AD patients, moisturizers were included as a standard measure when using topical treatments for AD, such as pimecrolimus.³⁶ A refrigerated moisturizer used in combination with crisaborole ointment may prevent irritation, burning, or stinging.⁹

Statement 5: TCS, TCIs, and PDE4-I may induce application site pain such as burning and stinging. Information and education on measures to prevent or treat these side-effects, such as testing/limiting application sites and concomitant use of a refrigerated moisturizer, can help optimize results and decrease skin irritation.

Few AEs such as irritation, burning, and stinging were reported in clinical studies using crisaborole but seem to be occurring more frequently in clinical practice.^16,9

Clinical trials report stinging or burning occurring in up to 8%, but the symptoms are usually transient, and 1.7% of patients withdrew due to these symptoms. In practice, clinicians have anecdotally noted that the rate of stinging seems to be greater than that reported in clinical trials, but generally, the stinging is mild and transient.^16,9 Topical medications can sting due to the stabilizers and preservatives in the vehicle cream or due to the medication itself. TCIs can sting, and this stinging is often correlated to the degree of inflammation in the area. Clinicians often apply TCS initially to calm down the AD, after which the TCI is better tolerated. Whether this technique applies to crisaborole is not clear but should be answered by future reports/ studies.^8,9

Before starting crisaborole therapy, inform and educate the patient and caregiver on measures that may prevent or quickly resolve irritation, burning, or stinging if it occurs.⁹ Best practice tips of the panel include the use of crisaborole with daily skincare, such as a gentle cleanser and a refrigerated moisturizer.⁹ Apply a patient age-appropriate regimen and patient education.⁹ Identifying patients prone to skin irritation may benefit from an in-office trial with a sample before prescribing the ointment.

Survey Results

A pre-meeting survey was conducted among the panel to share best practice standards and clinical pearls they use in prescribing crisaborole to mild-to-moderate AD patients. All eleven advisors completed the survey. Demographics, number of visits of AD patients, the severity of AD, and treatment are shown in Table 1. When asked: If Crisaborole is not your first choice, indicate why not? stinging (63% [7]), burning (40% [4]) and costs (91% [10]) were frequently mentioned. Six physicians also answered crisaborole was not used for other reasons, which included: Lack of payer coverage, Need to be off-flare to initiate the treatment to get a good response, It is not as effective and does not work as quickly as TCS or TCI, Other medications are effective and more readily available and with which there is more clinical experience. The advisors noted to specifically use crisaborole for various body locations such as the face (72% [8]), hands (91% [10]), eyelids (55% [6]), intertriginous areas (63% [7]), genitals (63% [7]), and feet (81% [9]). According to the advisors, they hypothesize that the small molecular size of crisaborole appears to allow better penetration on areas with thicker skin.

Table 1: Pre-meeting survey results
N=11
Topical corticosteroid (TCS), atopic dermatitis (AD)

When asked the main reasons to prescribe crisaborole, all (100% [11]) answered that there is a need for a nonsteroidal alternative. Other answers included TCS phobia (91% [10]) and TCI phobia (63% [7]) and suboptimal results with previous therapy (63% [7]).

When stinging or burning occurred with crisaborole use, the advisors discontinued the treatment more frequently in children than adults. For preventing and managing AEs, the advisors provided education before starting crisaborole treatment. Some tested patients’ tolerability to the treatment in the office prior to a prescription to determine the degree of stinging. Further, they recommended measures to reduce stinging, such as concomitant use of a gentle cleanser and refrigerated moisturizer, cooling the ointment in the fridge, and concomitant TCS or TCI use (Figure 6). Finally, the advisors agreed to avoid the application of crisaborole on severely flaring skin.

When asked about the patients’ response to crisaborole treatment within four weeks, forty percent of responders noted that on average, 20-50% of patients had improved, and 50% of the panel noted an improvement in over 50% of their patients (Figure 7 and 8).

Limitations

Measures to reduce burning and stinging that may occur when using crisaborole were developed using the authors’ expert opinion and clinical experience, and further studies are needed to support the possible benefits of these measures.

Conclusions

The review explored best clinical practices of crisaborole for mild to moderate AD patients and provided expert guidance for the real-world use of crisaborole ointment.

Atopic dermatitis is a common chronic inflammatory disorder in which patients experience a waxing and waning disease state that is punctuated by episodes of flares. If their disease is quiescent, then the patient continues good skincare by utilizing moisturizers and avoiding irritants. Patients will escalate and add topical medications at the first sign of a flare. Since every patient has a distinct disease course, some patients may never be fully clear while others clear between episodes. Recognition that patients with AD have a disease that often varies in severity and location on their body allows physicians to choose the appropriate treatments based on their clinical experience. The physician needs to educate their patient to escalate therapy accordingly at the first sign of disease in order to prevent severe flares. An eczema treatment plan is a necessity to ensure a smooth transition of therapy from baseline to flare. For mild to moderate AD patients, three topical options can be prescribed to control inflammation. Traditionally these medications have been divided into first and second-line therapy. However, the expert panel believes that the choice of a specific agent should be decided by the clinician based on factors such as disease severity, location, physician experience with the product, cost, and patient preference.

Crisaborole is a nonsteroidal PDE4-I with demonstrated safety and efficacy in patients aged three months and older with mild to moderate AD. It is a well-tolerated alternative to TCS or TCI and can be used on any cutaneous non-mucosal body site. It may be especially beneficial for areas with thicker skin, such as hands and feet, possibly due to improved penetration to the site of inflammation as a result of its small molecular size. There are no concerning serious safety signals associated with crisaborole. Crisaborole does cause a burning sensation in 8% of patients, but this is usually transient and may be minimized by the concomitant application of cool moisturizers. Consideration of in-clinic test site application of crisaborole to high-risk individuals may help identify those at risk and allow patient education, which may decrease the side effect and in turn improve adherence and outcome.

¹Associate Professor, Department of Medicine, University of Toronto, Toronto, ON, Canada
²Clinical Assistant Professor, Department of Dermatology, University of British Columbia, Vancouver, BC, Canada
³Clinical Professor, Director of Pediatric Dermatology, University of Alberta, Edmonton, AB, Canada
⁴Professor, Western University, London, ON, Canada
⁵Assistant Professor, Department of Medicine, Department of Pediatrics, University of Toronto, Toronto, ON, Canada
⁶Assistant Professor, Department of Pediatrics and Child Health, University of Manitoba, Winnipeg, MB, Canada
⁷Division of Dermatology, Sainte-Justine University Medical Center; Clinical Professor in Pediatrics, University of Montreal, Montreal, QC, Canada
⁸Division of Dermatology, Sainte-Justine University Medical Center; Clinical Professor in Pediatrics, University of Montreal, Montreal, QC, Canada
⁹Clinical Associate Professor, Department of Pediatrics, University of Calgary, Calgary, AB, Canada

Funding:
This Supplement was developed using the Authors’ Expert Opinion, supported by an unrestricted Educational Grant from Pfizer Canada.
Use crisaborole ointment in off-label settings is left up to the discretion of the treating health care professional after careful clinical evaluation.

Abstract:
Background: Atopic dermatitis (AD) is associated with epidermal barrier dysfunction. The chronic skin condition presents clinically with pruritus and recurrent skin lesions. The psychosocial impact of the condition is severe for most patients and their families.
Crisaborole, a topical PDE4 inhibitor, has demonstrated efficacy in patients with mild-to-moderate AD.

Objectives: A diversity of cases are presented that reflect real-world clinical use of topical crisaborole ointment, as a mechanism to help optimize patient care.

Methods: Evidence from the literature coupled with the panels’ expert opinion, experiences and, key insights reflect the panels’ clinical use of topical crisaborole ointment for AD and irritant dermatitis (off-label use) and how patients can benefit from its use, i.e., “what experienced specialists are doing across Canada.”

Results: The panel treated and presented cases that report on crisaborole ointment used as monotherapy, combination therapy, sequential therapy, and maintenance therapy. The presented cases aim to illustrate the diversity of crisaborole use concerning age range, skin type/ethnicity, and body location. Each case presents a summary of the learning points.

Conclusions: The presented cases reflect the panels’ real-world clinical experience with crisaborole for the treated patients. The panel suggested that crisaborole ointment provides a good safe alternative to TCS and TCI. Treatment with the ointment should be avoided on severely flaring skin and for those that experience irritation, burning, or stinging while testing it on unaffected skin areas.

Key Words:
Atopic dermatitis, Real-world cases, Topical PDE-4 inhibitor

Introduction

Atopic dermatitis (AD) is a lifelong inflammatory skin condition associated with epidermal barrier dysfunction and altered immune function, presents clinically with recurrent episodes of pruritic erythematous papules and plaques.¹ AD usually starts in infancy, where it affects up to 20% of children in North America, and is also highly prevalent in adults.² Two-thirds of AD patients are reported to have mild disease, 26% moderate, and 7% severe AD disease.³ The majority of patients are treated by primary care physicians who primarily use topical anti-inflammatory therapy for their mild-to-moderate AD cases.^4-13

The psychosocial burden of AD on patients and their families is enormous.¹⁵ The inflammatory skin disease increases the risk of other immune-mediated inflammatory atopic disorders, such as asthma, allergic rhinitis and food allergies, as well as mental health disorders in some.^15,16

Patients with AD should use gentle cleansers and moisturizers that are balanced to the skin pH in addition to behavioural measures such as avoidance of irritants and triggers.

AD is a chronic relapsing disorder with periods of quiescence punctuated by intermittent flares. When AD flares then treatments such as topical corticosteroids (TCS), topical calcineurin inhibitors (TCI), and more recently, phosphodiesterase-4 (PDE4) inhibitors should be considered, while continuing skincare and measures to avoiding triggers of AD. TCS and TCI treatments are widely used as monotherapy in cases of mild-to-moderate AD or in combination with systemic treatments for more severe AD involvement. These treatment regimens are supported by clinical guidelines and clinical pathways worldwide and have an established safety record.^4-13 Crisaborole ointment (Eucrisa, Pfizer), a unique topical prescription option for AD, is a PDE4 inhibitor with demonstrated efficacy in patients aged two and older with mild to moderate AD.¹⁶

The presented real-world case-based approach explores the role topical crisaborole can play in the prevention, treatment and maintenance of AD and other inflammatory skin conditions, in clinical practice. The selected patient cases aim to outline a diversity of cases that reflect real-world use of topical crisaborole ointment for patients with AD and other skin conditions, either as monotherapy or in combination with other treatments. Any discussion concerning off-label use is considered an expert opinion only.

Methods

Aim of the Project

This current real-world case project was conceived as a mechanism to help optimize patient care by recognizing the role crisaborole ointment can play in the prevention, treatment and maintenance of AD. Additionally, the project explores where this therapeutic agent could be used in managing AD in patients who require a combination of therapies. The cases intend to illustrate the authors’ real-world clinical experience rather than reflect controlled clinical trial data. Evidence coupled with the expert opinion, experiences, key insights and recommendations is presented and discussed. Recommendations given by the panel reflect the use of topical crisaborole ointment for AD and how patients can potentially benefit from its use, i.e. “what experienced specialists are doing across Canada”. Any discussion concerning off-label use is considered an expert opinion only.

The target audience for this publication is physicians and other health-care professionals who treat patients with AD.

Steps in the Process

The five-step procedure included a) project definition and panel selection, b) collection of information and preparation of cases, c) meeting to select cases for the publication, d) literature review to support the cases, and e) creation, review, and finalization of the manuscript.¹⁷

Role of the Panel

An expert panel of eight dermatologists and pediatric dermatologists, selected to represent the diverse geographical regions within Canada, who commonly treat patients with AD, was convened on November 9, 2019, in Toronto, as part of the semiannual Dermatology Update conference. The panel members reported clinical cases of pediatric and adult patients who were suitable candidates for crisaborole ointment treatment.

The panel members discussed the cases in the light of the supporting literature, then decided which cases would be included in the publication. The publication was prepared and reviewed by the panel members.

Topical Treatment for Mild-To-Moderate AD

Avoidance of triggers of AD flares and education are the first steps in the prevention, treatment, and maintenance of AD.6

Skincare Using Gentle Cleansers and Moisturizers

Skincare using gentle cleansers and moisturizers remains the cornerstone of treatment for all severities of AD. Daily use of this skincare regimen is supported by established guidelines and clinical pathways.^4-13 Moisturizers play an important role in combating and controlling xerosis, decreasing epidermal water loss, and restoring epidermal barrier function.^6,10 Moisturizers should be liberally and frequently applied and can be used alone for mild disease or in combination with other therapies regardless of the severity of their AD. ^6,10

TCS and TCI

If avoidance of triggers and the use of a daily skincare regimen with gentle cleansers and moisturizers are not effective, topical anti-inflammatory agents, such as corticosteroids (TCSs) or calcineurin inhibitors (TCIs) are used twice a day until the lesions have cleared.^3-13 TCS is the first-line anti-inflammatory option, available in a variety of strengths from mild to potent and very potent.^6,11 Side effects such as skin atrophy, purpura, telangiectasia, striae, focal hypertrichosis, impaired wound healing, allergic contact dermatitis, and acneiform or rosacea-like eruptions on the face are very uncommon when TCS is used appropriately.⁶ Both patients’ and parents’ fear of TCS and steroid phobia should be discussed to improve adherence and avoid under-treatment.⁶

TCI’s are another safe and effective treatment option, however short-term side effects such as skin burning, and pruritus, especially when applied to acutely inflamed skin and cutaneous viral infections, may occur.⁶ Patients and parents should be informed about these potential side effects to avoid premature discontinuation of treatment.⁶ TCIs are therapeutic agents often used for mild AD on the face, neck, and folds, and used in prevention and TCS reduction elsewhere on the body.

Systemic Therapy

For patients affected by more severe AD, agents that target immune responses and inhibit T cells by targeting Th1, Th2, Th22, phosphodiesterase-4 (PDE4), IL-4, and IL-31 are available.¹⁸ Phototherapy and traditional systemic therapies, including methotrexate, cyclosporine, and mycophenolate mofetil, can also be used off-label in severe AD.

Crisaborole Ointment

Crisaborole (Eucrisa, Pfizer), a topical prescription option for AD, is a PDE4 inhibitor with demonstrated efficacy in patients aged two and older with mild to moderate AD.16 Two, multicenter phase III trials, demonstrated early sustained control of mild-to-moderate AD in patients aged over two years with crisaborole ointment use over twenty-eight days.¹⁶ When compared to the vehicle, treatment with the 2% crisaborole ointment showed reduced pruritus, AD severity, and other signs of AD (erythema, exudation, excoriation, induration/papulation, and lichenification), although clinicians have expressed concerns about stinging and burning on at application sites.^16,19

A multicenter extension study indicated that crisaborole ointment for up to fifty-two weeks is safe.¹⁷ The extension study reported an overall 10.2% rate of crisaborole treatment-related adverse events such as dermatitis (3.1%), application site pain, stinging, burning (2.3%), and application site infection (1.2%).³ These events were considered mild, and no one withdrew from the study due to these adverse events.

Less common potential side effects included skin irritation and hives or welts, which may be due to underlying atopy. Given the good tolerability and safety profile, crisaborole ointment makes for an alternative steroid-sparing topical option to TCS and TCI.¹⁶

Data Gathering of Real-World Cases on Crisaborole Ointment Use

The panel members used a template for their case studies, which asked the following questions:

• What are the cases and the impact of the condition?
• What are the treatment options, and what treatment(s) were previously used for this case
• Why might crisaborole ointment work in this case, where does it fit and what were the results of the treatment?
• Did any adverse events occur? If yes, describe.
• What (if any) are the special circumstances related to this particular case, and which lessons are learned?

Patient evaluations were at baseline (start) and at eight weeks (+/- 5 days) using physician reported skin condition (SCORing Atopic Dermatitis Clinical assessment [SCORAD] score.²¹ SCORAD recorded AD location and percentage area (A), Intensity (B): Redness, swelling, oozing/crusting, scratch marks, skin thickening, dryness [the intensity of each of the following signs is scored as none (0), mild (1), moderate (2) or severe (3)] and subjective symptoms (C) [Sleeplessness: 0 = no sleeplessness and 10 = the worst imaginable sleeplessness, Itch: 0 = no itch and 10 = the worst imaginable itch]). Total SCORAD is the sum of A, B, and C, minimum score = 0, maximum score = 103.21 The impact of the skin condition after treatment regime use and adverse events were recorded at baseline (start) and week 8 (+/- 5 days) (end).

Some of the physicians used quality of life for the participants 15 years or younger as assessed by Children’s Dermatology Life Quality Index (CDLQI). The minimum score is 0, and the maximum score is 30, the latter corresponds with the most severe impairment of quality of life. Other scores used were severity of itching as assessed by the Pruritus score determined using the Numerical Rating Scale (Minimum score is 0. The maximum score is 10, the latter corresponding to the most severe itching imaginable by the patient).

Selected Real-World Cases

The panel selected a total of eleven cases that reported on realworld use of crisaborole ointment as monotherapy, combination therapy, sequential therapy, maintenance therapy, preventive therapy, and its application in dermatitis beyond AD. (Table 1). The presented cases aim to illustrate the diversity of crisaborole use concerning age range, skin type/ethnicity, body location, the severity of AD, and reports of off-label use.

Case 1: A 4½-year old girl with AD since the first months of life, which had recently increased in severity. The moderate-tosevere condition involved multiple sites, including hands and feet. Previous treatment with various TCS formulations was unsuccessful. When crisaborole started, mometasone ointment was continued as needed on the lesions on her body. The rationale for starting topical 2% crisaborole ointment was the failure of previous treatments and a specific interest in improving the skin condition of her hands and feet. Her skin condition markedly improved over the eight week treatment period (Figure 1A-1J). No adverse events occurred, and the ointment was well tolerated even on the face.

Learning point: Crisaborole is a well-tolerated (even on the face) alternative for TCS and is effective on hands and feet.

Figure 1A – 1D

Figure 1E and 1F

Figure 1G and 1H

Figure 1I and 1G

Case 2: For four months, a 4-year-old boy had suffered from AD, primarily on the face, antecubital, and popliteal fossa. He had almost constant pruritus and open, erythematous skin. His interaction with other children was poor, and both the patient and parents had difficulty sleeping. Previous long-term TCS treatments lacked success. Moreover, his mother was concerned about prolonged steroid use and requested trying crisaborole ointment. After eight weeks of crisaborole ointment application, his skin condition had greatly improved (Figure 2A and 2B). Although at first, the ointment caused skin irritation, this was easily alleviated with the use of a moisturizer.

Learning point: Crisaborole seems to induce irritation, burning, and stinging more frequently in clinical practice than reported in clinical trials. The patient experienced irritation, burning, and stinging in the areas where crisaborole was used. Information and education on measures to prevent or to treat these side-effects were effective. The advice given included the use of a refrigerated moisturizer, frequently applied before and after application of the ointment to optimize crisaborole results and decrease irritation. The mother was encouraged to continue treatment after the physician discussed the expected outcomes of the therapy. The irritation was alleviated with the use of a moisturizer as instructed.

Figure 2A and 2B

Case 3: A 29-year-old neonatal intensive care unit (NICU) nurse developed hand dermatitis one year ago. During work, she frequently used a hand sanitizer causing pruritus and painful fissures. She had a negative history for AD, and other atopic disorders and Patch tests were negative. The eruptions cleared when she was on holiday. After consultation with the occupational health department for help and guidance, she received a special hand sanitizer. She refused TCS as she was concerned about developing skin thinning. Within eight weeks of starting crisaborole ointment, the condition had resolved. The ointment was well tolerated, and she resumed her work as a NICU nurse (Figure 3A and 3B).

Learning point: The patient with occupational irritant hand dermatitis did not want to use TCS. The alternative treatment with crisaborole ointment was successful for this patient. Use of crisaborole in the treatment of irritant contact hand dermatitis is off-label.

Figure 3A and 3B

Case 4: A 68-year-old woman with a history of rosacea also had recurrent facial eruptions. Patch testing was positive to Kathon CG, which was found in her laundry product which she had since avoided. Since TCS were unsuccessful, treatment with crisaborole ointment was started, used in combination with ceramides containing cream as needed. Her skin condition markedly improved within two weeks (Figure 4A – 4D).

Learning point: The ointment may be a useful alternative for TCS for facial areas in patients with concomitant facial inflammatory skin conditions. Although crisaborole may induce irritation, burning, and stinging, in this patient with underlying rosacea, the product was well tolerated. Topical steroids can induce a rosacealike eruption. Crisaborole did not aggravate this patient’s rosacea. Patch testing was useful in identifying the causative allergen. The use of crisaborole in allergic contact dermatitis is off-label.

Figure 4A and 4D

Case 5: An 11-month-old baby-boy had facial AD from the age of nine months. He had coincident acute myelogenous leukemia (AML) and was recovering from chemotherapy. His parents were concerned about TCS and TCI being immunosuppressive agents and due to his ongoing AML treatment refused them. Crisaborole ointment seemed a good alternative option. His skin condition improved within an eight week observation period, and no adverse events occurred (Figure 5A – 5D).

Learning point: In immunosuppressed or otherwise vulnerable patients, crisaborole ointment is an effective alternative to TCS to treat AD even on the face. Parental wishes to not use TCS or TCI were granted because crisaborole’s mechanism is not immunosuppressive. Although crisaborole is approved for use in individuals 2 years of age and older, it was safely and effectively used in this infant.

Figure 5A and 5D

Case 6: A 2-month-old baby boy presented with diffuse xerosis and AD present since three days of age. His condition impacted the entire family. His mother had applied Vaseline six times a day and TCS twice a day. He had not responded to treatment with several different types of TCS. The physician was concerned about absorption and possible adrenal axis suppression. After eight weeks of crisaborole ointment use, pruritus had subsided and both the baby and his family were able to sleep through the night (Figure 6A and 6B). Before starting treatment with crisaborole ointment, he had regularly had skin infections with MRSA, which did not reoccur since the start of the crisaborole ointment.

Learning point: Crisaborole proved to be a useful alternative for TCS where absorption and possible adrenal axis suppression were a major concern. Of interest is the resolved recurrent infection since the use of crisaborole, which may be attributed to the improved skin condition. Crisaborole is approved for use in individuals with AD two years of age and older.

Figure 6A and 6B

Case 7: A 15-year-old male had recurrent resistant atopic dermatitis and dyspigmentation from chronic TCS use. Treatment of the generalized flares and superinfection consisted of intravenous antibiotics and oral cyclosporine, to which he had a good initial response. To address his concern about TCS use and the desire for a simpler regimen, twice daily application with crisaborole ointment was started while continuing the cyclosporine. After eight weeks of use, he had an excellent response, with marked improvement in his quality of life. Whenever the patient stops topical crisaborole, some AD returns (Figure 7A and 7B).

Learning point: The use of crisaborole ointment in combination with systemic therapy was effective for this patient. The ointment is to be applied at the first sign of a flare before lesions develop and avoided the need to increase systemic therapy. As a result, he gained confidence in controlling his skin condition and improving his outlook on his situation.

Figure 7A and 7B

Case 8: A 5½-year-old boy had mild-to-moderate AD since the age of three and recently developed symptomatic hand and feet involvement. The rationale for crisaborole use on his hands and feet was the suboptimal response to previous TCS/TCI therapy. Concomitant use of TCS and TCI was continued together with crisaborole. His skin had almost cleared after eight weeks of crisaborole ointment use (Figure 8A – 8D).

Learning point: An incremental benefit of adding crisaborole as part of a combination regimen with TCS and TCI TCI introduces new possibilities for patients with AD on their hands and feet.

Figure 8A and 8D

Case 9: Since the first months of life, a 5-year-old male has had moderate-to-severe AD with symptomatic painful involvement of his hands, impacting daily activities. He had difficulty handling toys and interacting with other children and their parents. TCS and TCI treatments were not successful. With crisaborale, his hand palms and wrists’ involvement almost completely cleared. (Figure 9A – 9E).

Learning point: Effective penetration of crisaborole on thicker skin such as hand-palms and foot-soles may facilitate improvement in these special sites.

Figure 9A and 9B

Figure 9C and 9E

Case 10: A 4-year-old girl had AD. TCS therapy was started for her flaring disease. Her mother was concerned about vaccines and TCS use. Crisaborole ointment treatment was started to address the mother’s concerns. At eight weeks of ointment application, there was an 80% clinical improvement; however, some moderate AD persisted at some sites which required strong TCS.

Learning point: Although the crisaborole ointment did not completely resolve the disease, the mother preferred it to TCS for milder lesions and wished to reserve TCS for more resistant lesions.

Figure 10A and 10G

Case 11: A 12-year-old male with AD since infancy had involvement of the hands and limbs. His condition failed to show improvement from intermittent TCS. The rationale for starting crisaborole ointment was the family’s frustration with the lack of results and a possible penetration advantage of the ointment on the hands. A left/right assessment of clobetasol versus crisaborole ointment was conducted. His mothers’ perceptions were that his hands both improved, but the crisaborole ointment was more effective than clobetasol. On the arms and legs, both treatments were successful, but clobetasol outperformed crisaborole ointment. The therapy was continued after the eight weeks study period as the family was happy with the treatment response. No adverse events occurred. Subsequently, mom used crisaborole alone on his hands and had ongoing good maintenance and prevention of flares. (Figure 10A – 10G). Follow up results are shown in Figure 11A – 11E.

Learning point: The crisaborole ointment performed better on the hands than clobetasol, however when used on the arms and legs, the reverse was the case, indicating that the ointment may be particularly useful on thicker skin areas.

Figure 11A and 11E

Discussion

For each case, the age, skin type, underlying skin condition, rationale for using crisaborole, and in some cases, treatment duration were highlighted as well as its role as part of a maintenance/prevention and treatment regimen. The cases presented a spectrum of clinical responses to crisaborole, including instances of poor response, such as in case 10, where AD persisted, and TCS was further needed. The panel discussed challenges of recognizing and managing AD in darker skin which may be addressed using crisaborole ointment, although studies are needed to confirm possible benefits. Most of the cases were atopic dermatitis, the approved indication. Two other types of dermatitis (hand dermatitis, allergic contact dermatitis) were included although they have not approved indications since these conditions are often difficult to treat and do not always respond to topical steroids. In addition, on the face, topical steroids may be associated with a greater potential for adverse events.

Steroid Phobia

Steroid phobia refers to the negative feelings and beliefs related to TCSs experienced by patients and patients’ caregivers. The panel expressed concerns that this phenomenon may be a contributing factor in treatment failure in AD patients. A systematic review²² found that TCS phobia is present across all cultures and that adequate information for patients and parents is lacking. The authors of the systematic review propose that the sources from which patients are receiving information about TCS may be targetable for intervention to increase adherence to TCS treatment regimens.²²

Crisaborole can be an effective alternative for TCS and TCI, especially in patients with conditions requiring long-term TCS or TCI use.

In case of safety concerns (even when subjective) with TCS and TCI use in young patients or concerns about steroid absorption in all groups, patients can safely use crisaborole ointment. Moreover, preservatives in crisaborole pose no safety issues. The panel agreed that crisaborole ointment provides a good safe alternative to TCS and TCI in such cases, enhancing treatment adherence and thus outcomes.

Irritation, Burning and Stinging

Crisaborole seems to induce irritation, burning, and stinging more frequently in clinical practice than reported in clinical trials.^3,6,19 This side effect was also reported for two of the presented cases (case 2 and 4). The panel suggested that in their experience, irritation, burning, and stinging are more quickly resolved than in the case of TCI use, where similar side effects are also observed. If TCI related stinging occurs most clinicians will apply steroids temporarily and then subsequently TCIs are usually tolerated.

The panel recommended providing information on this issue and education on measures to prevent or to treat it before the start of the treatment with crisaborole. The panel recommended frequent use of a refrigerated moisturizer before and after application of the ointment, and the use of an anti-itch lotion as needed throughout the day. The panel further suggested that it may be helpful to have patients testing crisaborole on healthy skin. Modify or discontinue the treatment if the formulation triggers burning or stinging even on healthy skin with concomitant use of a refrigerated moisturizer. The panel discussed avoiding crisaborole ointment use on severely flaring skin and starting with TCS until the flare is controlled, followed by crisaborole ointment.

Antibiotic Resistance

Antibiotics are commonly used as part of the management of AD. However, only a minority of patients with AD have clinically significant S. aureus infection. Moreover, data is lacking for highly beneficial outcomes with exclusive use of antibiotics in the management of AD.²³ Case 6 shows an example of the possible use of crisaborole as a steroid-sparing and antibiotic-sparing agent. Because of antibiotic resistance, the use of the crisaborole ointment may be of interest and aligns with current emphasis on antibiotic stewardship in AD. Anti-inflammatory agents control eczema, which leads to less frequent infections and less antibiotic use.

Combination Treatment

Combining or alternating crisaborole with TCS or TCI may be successful for more severe disease. The ointment was safely used in time-intervals between the application of a moisturizer, TCS, or in combination with systemic therapy. Several cases showed a marked improvement in the skin condition of the treated patients and no adverse events.

Specific Body Locations

Case 4 shows an example of the safety and tolerability of crisaborole when used on specific sites (e.g., face and lips). An incremental benefit of crisaborole use as part of a combination regimen was shown in a patient (case 8) who recently had AD involvement of his feet, with hyperkeratosis and desquamation.

The rationale for crisaborole use, in this case, was good absorption of the ointment due to the relatively small size of the molecule allowing better penetration.

Case 11 showed beneficial crisaborole use on the hands, which did not improve with intermittent TCS application. This patient conducted a real-time comparative test using clobetasol on one side of the body and crisaborole on the other. Crisaborole worked better on the hands while clobetasol showed better results on his arms and legs.

The use of crisaborole for non-AD (case 3) was shown in a patient with occupational HD, which resulted in complete response. Advisors recommended further studies of crisaborole on the hands and feet (e.g., the study of occupational hand dermatitis and penetration study) to support the use of the ointment for these complex areas.

Table 1: Summary of the eleven cases studies
Case 1: TCS^a: Betametasone dipropionate 0.1% ointment, Mometasone ointment, TCI^b. Tacrolimus 0.1% ointment, Skincarec: Hydratation-Eucerin, Aquaphor, Aderma cleanser and hydrating agent.
Case 2: TCS^d: Desonide cream BID x 1 year, Hydrocortisone 17 valerate UNG BID x 1 year.
Case 3: TCS^e: Hydrocortisone cream
Case 4: TCS^f: 1% hydrocortisone cream
Case 6: TCS^g: Hydrocortisone 2.5%g then switched to desonide for body, Dermasmoothe FS for scalp and face. Then switched to hydroval 0.2% ointment to entire body.
Case 8: TCS^h: 0.1% betametasone valerate ointment (body), 0.1% protopic ointment (face).
Case 9: TCSⁱ and TCI: Betametasone dipropionate 0.1% ointment, Mometasone ointment, Tacrolimus 0.1% ointment.
Case 10: TCS^j: Begin with strong corticosteroids, Desonide ointment for the face, Betamethasone valerate 0,1% ointment for the hands and feet.
Case 11 : TCS^k : Clobetasol.

Atopic dermatitis (AD), Twice daily (BID), Crisaborole ointment (CO), Adverse events (AEs), Neonatal intensive care unit (NICU), Hand Dermatitis (HD), Medical history (Hx), Acute Myelogenous Leukemia (AML), Intravenous (IV) Oral (PO).

Maintenance Therapy

The panel discussed the spectrum of clinical response of crisaborole used in adjunction to a moisturizer as maintenance therapy and suggested that crisaborole ointment should start at the first sign of a new flare before the development of lesions. TCS should be added if it is not successful. Currently, data on the use of crisaborole ointment for long term maintenance therapy is lacking; however, the panel suggested further studies of crisaborole as maintenance therapy.

Conclusion

The discussed cases reflect the panels’ real-world clinical experience with crisaborole for the treatment of patients with AD and the off-label treatment of irritant dermatitis. The panel suggested that crisaborole ointment provides a good safe alternative to TCS and TCI. Use of crisaborole should be avoided on severely flaring skin and for those that experience irritation while testing it on unaffected skin areas.

Acknowledgement

The authors acknowledge and thank Anneke Andriessen, PhD, for her invaluable assistance with preparing this manuscript.

Limitations

The cases are intended to illustrate the real-world experience rather than reflect a controlled clinical trial data environment, nor do they presented cases mirror statistical outcomes. Use crisaborole ointment in off-label settings is left up to the discretion of the treating health care professional after careful clinical evaluation.

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¹Hospital for Sick Children, Toronto, ON, Canada
²University of Calgary, Calgary, AB, Canada
³University of British Columbia, Vancouver, BC, Canada
⁴Toronto Western Hospital, University Health Network, Toronto, ON, Canada and Department of Dermatology, Brown University, Providence, RI, USA
⁵University Health Network, Toronto, ON, Canada
⁶Centre hospitalier universitaire Sainte-Justine, Montreal, QC, Canada
⁷British Columbia Children’s Hospital, Vancouver, BC, Canada
⁸Eczema Society of Canada / Société canadienne de l’eczéma, Keswick, ON, Canada

This manuscript was previously disseminated by Eczema Society of Canada Copyright© by the Eczema Society of Canada / Société canadienne de l’eczéma July 2016; revised 2017. All rights reserved. Third Edition

About Atopic Dermatitis

Eczema (atopic dermatitis), is a chronic, pruritic inflammatory skin condition that follows a relapsing course affecting people of all ages, although it is more frequent in children. Eczema is most often diagnosed and managed by primary care providers. This article aims to provide practical guidance to primary healthcare practitioners who care for patients with eczema. The Eczema Society of Canada/Société canadienne de l’eczéma convened a group of Canadian dermatologists with extensive experience in managing paediatric and adult patients with atopic dermatitis, to develop practical recommendations for the management of atopic dermatitis. They developed clinical recommendations based on expert consensus opinion and the best available medical evidence. The experts developed recommendations that focus on three key areas of managing patients with eczema: (1) patient/caregiver education, (2) addressing skin barrier dysfunction and (3) inflammation control. Therapeutic education directed to the patient or main caregiver(s) has been demonstrated to improve QoL.¹ While complete guidelines on AD are available,^2-5 these guidelines may not be practical for everyday clinical practice in primary care, nor are they specific to the Canadian healthcare system.

Abbreviations: AD – Atopic Dermatitis, QoL – Quality of Life, SOA – Sedating Oral Antihistamine, TCI – Topical Calcineurin Inhibitors, TCS – Topical Corticosteroids

Background

• Atopic dermatitis (AD)-also commonly referred to as eczema or atopic eczema-is a chronic, pruritic, relapsing inflammatory skin condition that impacts quality of life (QoL) and places a significant burden on patients and families.
• It can affect people of all ages but it is more frequent in children.
• Eczema is characterized by periods of acute worsening symptoms, known as flares, alternating with periods of symptom remission, but some patients do not have any remission.
• Patients often have associated atopic disorders, such as allergic rhinoconjuncitivitis, food allergies and/or asthma.
• The onset of eczema is typically between 2 and 6 months of age, although it can begin at any age. It was previously thought that eczema resolved or improved by adulthood in most cases, but evidence suggests that it is a chronic condition that may persist into adulthood.^6-8
• Eczema is caused by a dysfunctional skin barrier and dysregulation of the immune system, due to genetic, immunologic, and environmental factors. Pruritus is the most notable feature of eczema, which is at the centre of much of the disease burden for patients and their families.

Diagnosis & Assessment

• Eczema is most often diagnosed and managed by primary care providers.⁹
• Eczema is diagnosed based on the morphology and distribution of the patient’s skin lesions, associated clinical signs, and family history (Table 1).¹⁰ Eczema can range from mild to severe, based on body surface area involvement, extent of eczematous lesions, and the impact on a patient’s QoL.
• At this time, eczema remains a clinical diagnosis. In select cases additional testing may be performed, such as a biopsy or patch testing, to rule out other conditions, but this is usually unnecessary. If the diagnosis is unclear, referral to a dermatologist should be considered.

Quality of Life in Eczema Assessment

• Eczema has a significant impact on QoL for patients and their families. Physicians should consider addressing this impact on QoL with their patients and patients’ families, in addition to assessing the signs and symptoms of the disease.
• Sleep is disturbed, often for the whole family. Healthcare providers should address itch, sleep loss, and disease impact on mood, activities, behaviour and self-esteem, when diagnosing eczema and formulating a management plan.
• The impact of AD on QoL for the patient and his or her family is often very significant. The level of impact has been found to be similar and at times can surpass the effect that diabetes has on the family.¹¹

Minimizing and Controlling Flares

• Eczema is a relapsing-remitting, chronic disease with cyclical periods of relative quiescence and periods of flares.
• Currently, there is no cure for eczema. As such, the main goal of eczema management is to improve baseline inflammation and xerosis and to reduce the frequency and severity of flares. For some patients, treating baseline disease activity will involve emollient use only. For others it will involve the use of emollients and topical anti-inflammatory medications to any inflamed areas. In periods of flare, treatment needs to be increased beyond this baseline.
• For those mild disease and mild flares, adding a topical anti-inflammatory medication to their emollient regimen may be necessary.
• For others with more severe eczema, a temporary increase in the potency of topical anti-inflammatory medications may be required.
• For patients with frequent flares and flares that require high-potency topical corticosteroids, referral to a dermatologist is recommended.

Patient Education

• Suboptimal treatment and poor adherence to therapy are common in patients with eczema, much like in patients with other chronic diseases that require regular intervention. Therefore, therapeutic education is particularly important in the face of many sources of potentially misleading or inaccurate information, or patient misconceptions and fears present in the community.¹²
• Patient and caregiver education is a key aspect of successful eczema management.¹³ Studies have demonstrated that therapeutic patient education increases adherence to therapy, increases the use of moisturizers, and decreases fear of medications.^14-16

Patient counselling should focus on the following key points:

• Eczema is a chronic disease. There is no cure, but control of the disease can be achieved. Eczema typically goes through periods of flares and remissions. Moisturizing is the mainstay of therapy during remission, and prescription treatments are needed for any areas of inflammation.
• Eczema flares can be managed by hydrating the skin (bathing and moisturizing appropriately) and reducing inflammation with topical medication.
• Undertreating, starting treatment too late, or stopping treatment too soon, should be avoided. Treatment of eczema flares should begin at the first sign of inflammation. Patients and caregivers often stop treatment before the skin is fully clear of lesions, mistakenly believing that the vast improvement they have seen means the skin is “clear enough.”
• Clinicians should encourage patients and caregivers to make sure the skin is completely clear of lesions before stopping treatment, since even though eczema flares may seem to be much less severe, the patient still has chronic active inflammation, and often the skin rapidly becomes worse.
• Patients need to be counselled on how to apply the medication, as applying the treatment sparingly may contribute to under treatment.
• Adherence to therapy is essential for the optimal management of eczema. Poor adherence may be the most significant barrier to optimal care in eczema. In a survey of 200 eczema outpatients, 24% admitted that they did not adhere to treatment, and experts estimate this percentage could be significantly higher.⁵ Healthcare providers should counsel patients and caregivers about the importance of adhering to treatment.
• Trigger avoidance:
  • Patients should be counselled to attempt to identify and avoid their triggers, and to understand that some eczema flares occur despite strict trigger avoidance and diligent skin care. This is often a source of frustration for patients.
  • Many eczema flares do result from some environmental trigger. Common triggers include harsh or fragranced soaps and self-care products, rough fabrics, overheating and sweating, and winter weather. Often these triggers can be identified but not avoided, such as weather changes.
  • Lifestyle can impact eczema as well, such as sweating for a young athlete. Instead of advising the patient to avoid pleasurable activities, help the patient learn about ways to manage the eczema flare that may follow an activity or exposure to an eczema trigger.
  • Additional actions can be taken to help the condition, such as keeping nails trimmed short and filed smooth to help reduce damage done by scratching.
  • Distraction can also be helpful during episodes of acute itch, particularly activities that keep the hands busy.
• Patients and caregivers often seek causes or cures for eczema, which diverts attention away from the treatment plan. Patients should be counselled on the chronicity of atopic dermatitis, and reminded that broad panel allergy testing and restrictive diets are not recommended in the absence of signs and symptoms consistent with an IgE-mediated allergy.
• For additional patient support, information and education, recommend reliable sources, such as the Eczema Society of Canada/ Société canadienne de l’eczéma, Canadian Dermatology Association, American Academy of Dermatology, National Eczema Association (USA), or National Eczema Society (UK)

Written Eczema Care Plans

• A written eczema care plan is a recommended tool to improve therapeutic outcomes.^{17, 18} Patients and caregivers may benefit from having a written plan in order to carry out the multi-step plan of caring for eczema, which often includes specific bathing and moisturizing recommendations and instructions for using prescription medications (type and dosage). For a sample written eczema care plan, see Figure 1.

Skin Care

Moisturizers

• Frequent application of moisturizers is the cornerstone of eczema management,¹⁹ helping to decrease itch, preventing and reducing flares, and decreasing the need for prescription medications.
• Xerosis results from skin barrier dysfunction and is present to some degree in most patients with eczema. Moisturizers are used to reduce xerosis, which reduces itching, and they also reduce transepidermal water loss.²⁰
• For patients with mild eczema, frequent and consistent use of moisturizers may sufficiently manage the disease. In moderate to severe disease, moisturizing is still a fundamental part of treatment. Patients may need to be explicitly counselled on how to use moisturizers in conjunction with other topical prescription treatments.
• Patients should select moisturizers that are soothing and do not irritate the skin. Ideal moisturizers contain varying amounts of emollient, occlusive and humectant ingredients. While thicker products that both moisturize and provide a barrier are recommended, there are many moisturizers to choose from and patient preference is important.
• The consistent use of a moisturizer that is well-tolerated by a patient is more important than the specific product selected.
• There is insufficient evidence to recommend a specific optimal regimen for use of moisturizers. However, this consensus group suggests that generous application, one to several times a day, is necessary to help minimize skin dryness. It is highly recommended to apply moisturizers immediately after bathing or any water exposure to improve skin hydration.^{21, 22}

Barrier Repair & Barrier Repair Products

• Patients with atopic dermatitis have impaired skin barrier function, partly due to deficiencies in ceramides (lipids) and filaggrin (a protein), components of the outer skin barrier. These deficiencies contribute to a degraded skin barrier that allows bacteria, irritants, and allergens to enter the skin, and also allows moisture to escape.²³ To address this, ceramides are increasingly available in over-the-counter moisturizers, as well as one prescription barrier repair treatment.

Bathing & Showering

• Daily bathing is often recommended for patients with eczema; however, there is no evidence to support a standard recommendation for the frequency, duration or the method of bathing. Moisturizing after bathing is strongly recommended.^{21, 22}
• Clinicians can recommend that patients bathe or shower (5-10 minutes) in warm, plain water once daily, or every other day, based on patient preference (e.g., baths may sting open eczema lesions making daily bathing challenging).
• Gentle cleansers may be used only on areas that need cleaning, and should be used at the end of the bath or shower. Bathing using this method should not aggravate eczema.
• Moisturizing should immediately follow bathing or showering, since exposure to water can exacerbate eczema if the skin is not moisturized soon after exiting the water.
• Evidence is lacking to support the use of bath additives such as oils, emollients, bath salts, and most other products.

Inflammation Control

Topical Corticosteroids

• Appropriate use of topical corticosteroids (TCS) is a safe and effective first-line therapy in the treatment of the inflammatory component of eczema.²⁴
• Consider factors such as the age of the patient, areas of the body to be treated, xerosis, and patient preference when prescribing appropriate topical corticosteroids.
• Selecting the appropriate agent, including the appropriate strength, can be challenging. In general, low potency TCS (classes VI and VII) are recommended for the face, neck, skin folds, and groin, for both paediatric and adult patients.
• Moderately potent medications (classes III, IV, and V) are recommended for the trunk and extremities. Higher potency TCS may be required for refractory eczema or lichenified areas.
• Consider referral to a dermatologist in these cases.
• Once to twice daily application of TCS are the generally recommended treatment during an acute eczema flare.
• Treatment should be stopped once the affected areas are smooth to the touch and no longer itchy or red.
• If no response to treatment is seen after 1 to 2 weeks, re-evaluate to consider other diagnoses or treatment plans. With appropriate use, the incidence of adverse events is minimal.²⁵
• When prescribing combination treatments, TCS strength should be taken into consideration, as the TCS could be of higher potency than is appropriate.
• Patients and caregivers may fear the side effects of pharmacological treatments. Fear of topical corticosteroids is common and should be recognized and addressed. This may be particularly important for paediatric patients.
• Addressing fears and concerns may help improve adherence and avoid under-treatment or non-treatment.
• Patients who are using corticosteroids over the long term should be monitored, and should have regular physical examinations to watch for cutaneous side effects. Monitoring of eczema patients for systemic side effects from topical corticosteroids is not routinely recommended.^{26, 27}
• In patients who have good adherence to their treatment plan and experience periods of remission, but flare frequently in predictable areas, maintenance treatment with topical corticosteroids may be suitable. Intermittent application (one application 1 to 2 times a week) of a moderately potent topical corticosteroid is recommended for proactive treatment on areas that are commonly at risk of flare.²⁸

Topical Corticosteroid Side Effects

• As with all medications, TCS can have side effects (Table 2). However, when they are used appropriately, the incidence of side effects is low, and patients should be counselled accordingly.²⁹
• The burden of under- and untreated eczema usually outweighs the risks associated with TCS.³⁰

Topical Calcineurin Inhibitors

• Topical calcineurin inhibitors (TCI) (i.e. tacrolimus and pimecrolimus) are a class of anti-inflammatory medications that are a recommended safe and effective second-line therapy option for treatment of acute flares of eczema.³¹
• Whereas TCS are generally considered first-line topical treatment for eczema, TCI can also be used off-label as first-line therapy in select cases, particularly for areas that are sensitive to the adverse effects of TCS, such as the eyelids.
• TCI are also appropriate second-line therapy for eczema that does not respond to TCS or in patients intolerant of TCS.
• TCI can also be used as a preventive therapy, 2 to 3 times a week in areas of predictable flares similar to the preventative strategy described for TCS above.³²
• Proactive, intermittent use of TCI has been shown to be more effective than the use of emollients alone.^{33, 34}

Topical Calcineurin Inhibitor Side Effects

• Mild to moderate burning or stinging sensation of the skin can occur with TCI use, and patients and caregivers should be counselled about this possible reaction.
• Patients who use tacrolimus may have flushing of the face when they consume alcohol.
• Based on concerns about an increased risk of cancer with the use of TCI use, the US Food and Drug Administration (FDA) issued a black-box warning shortly after the class of medications came on to the market. Shortly after the FDA warning was issued, Health Canada issued a similar warning. However, TCI have been available for over 15 years and recently published data does not support those concerns.^35-39 Healthcare providers should be aware of the black-box warning and discuss it with patients.

Adjunctive Therapies

Antimicrobials

• Skin infections can worsen eczema and should be addressed when present.
• Clinical signs of infected eczema include crusting, oozing, and pus.
• Gram-positive bacteria, in particular Staphylococcus aureus, is frequently found on the skin in eczema.⁴⁰
• Mild infection may be treated with a topical antibiotic adjunctively with a topical anti-inflammatory agent.
• The routine use of topical antistaphylococcal antibiotic treatment in the absence of clinical signs of infection is not recommended.⁴¹
• When clinical signs of bacterial infection are seen, swabs for culture and sensitivity should be considered, partly because of the increased prevalence of resistant organisms, and empiric oral antibiotics targeting streptococcal and staphylococcal infections can be started.
• In patients who frequently show clinical signs of secondary bacterial infection, consider bleach baths as prophylactic therapy.⁴²

Bleach Baths

• In patients where infections are common, bleach baths can be done once to twice per week, and consist of bathing in a dilute solution of bleach and clear warm water.⁴³
• Patients and/or caregivers can create a dilute bleach bath at home by adding 120 mL (1/2 a cup) of regular strength household bleach (6% sodium hypochlorite) to a full standard-size bathtub of warm water (which is usually about 150 litres). This concentration of bleach is quite low (0.005%).
• For smaller bathtubs, patients may use 1 teaspoon (5 mL) of regular bleach for every 5 litres of water.⁴²
• The bleach and clear water should be mixed well, and the patient should bathe in the solution for 5 to 10 minutes, thoroughly rinsing the skin after with warm clear water.
• Rinsing should be immediately followed by application of prescription treatments, if needed, and moisturizers.
• Patients and caregivers should be explicitly counselled on how to perform the bleach bath, including how to select the correct concentration of bleach and safe dilution practices.

Managing Viral Infections

• Viral infection with herpes simplex virus can cause eczema herpeticum, a potentially life-threatening condition.
• Swabs for viral detection (such as viral culture, or polymerase chain reaction) should be performed in suspected cases of eczema herpeticum, in addition to initiation of treatment with an appropriate antiviral agent.⁴⁴
• Eczema coxsackium is a form of hand-foot-and-mouth disease in patients with eczema that is more extensive than routine hand-foot-and-mouth disease, and can look similar to eczema herpeticum.
• Molluscum contagiosum occurs more commonly in eczema patients and the presence of the virus can lead to eczema surrounding the mollusca, potentially exacerbating an eczema flare.

Antihistamines

• Due to a lack of evidence of their efficacy in patients with eczema, non-sedating oral antihistamines are not recommended for use.⁴⁵
• Sedating oral antihistamines (SOA), such as hydroxyzine and diphenhydramine, can be used in patients whose disease significantly interferes with sleep.
• It should be noted that long-term use of SOA may lead to a reduction in the efficacy and sedative effects of the treatment.⁴⁶
• Control of inflammation and itch, through the use of previously discussed prescription anti-inflammatory medications and appropriate bathing and moisturizing may mitigate the need for sedating antihistamines in many patients.
• Patient reliance upon regular antihistamine use should be an indication that the treatment plan is not optimally managing the condition.⁴⁷

Allergy Testing & Restrictive Diets

• The relationship between eczema and allergy is complex. While children with eczema have a significantly higher incidence of food allergies, food does not cause eczema flares for most patients.
• In an AD patient who has confirmed food allergies, exposure to the allergenic foods can induce urticaria, which can indirectly worsen the eczema.
• If a patient shows true allergic signs and symptoms such as urticaria or anaphylaxis to a food, that food should be avoided and an epinephrine auto injector should be prescribed, until an allergist/immunologist can be consulted.
• Routine allergy testing with eczema as the only symptom is not currently recommended.
• Broad spectrum panel testing for a variety of foods is not recommended, as it often leads to a number of false positive results.⁴⁸
• Food elimination diets or restrictive diets are not recommended as an eczema intervention.
• Excessive, prolonged food elimination diets, especially in children, may lead to weight loss, poor growth, and nutritional deficiency.⁴⁹

Supplements & Alternative Therapies

• There is limited evidence to support the routine use of dietary supplements and alternative medicines for the treatment of eczema. However, some patients may find dietary supplements or alternative interventions to be helpful.
• If the dietary supplements or interventions are not harmful, the patient should be counselled and supported accordingly. However, if these interventions could be harmful, patients should be counselled and cautioned.
• Extra caution should be taken in the case of infants and children.

Refractory and Severe Eczema

• Phototherapy⁵⁰ and/or systemic immunomodulatory agents may be necessary for refractory and severe eczema, and they should be used by health care providers versed in their use.⁵¹
• Phototherapy, specifically broad- and narrow-band UVB, can be used for pediatric and adult patients with AD. It is a safe and effective treatment for most patients, but a major barrier to its use is accessibility as it requires visits to a physician’s office multiple times per week. Furthermore, long term side effects, such as skin cancer, have not been well-established in the paediatric population.
• Cyclosporine, methotrexate, azathioprine and mycophenolate mofetil are the systemic agents commonly used for atopic dermatitis. All of these agents may cause significant adverse events and require regular monitoring, so they should be used with caution and after appropriate discussion of their risks and benefits with patients and their families. Specific guidelines for their use, including dosing schedules and adverse effects, are beyond the scope of this review.
• Referral to a dermatologist should be considered in patients with refractory eczema in whom systemic therapy is being contemplated.

Systemic Corticosteroids

• Systemic corticosteroids, such as prednisone, are not recommended for the routine management of atopic dermatitis.
• While systemic corticosteroids can rapidly ameliorate the signs and symptoms of an acute eczema flare, patients often have a disease flare upon withdrawal of the corticosteroid.
• Given the long-term consequences of chronic systemic corticosteroid use, they should be avoided whenever possible in patients with atopic dermatitis.⁵²

1. University of British Columbia Student Health Services, Vancouver, Canada
2. Department of Dermatology and Skin Science, University of British Columbia, and The Pediatric Allergy Dermatology Centre (PADC), Vancouver, Canada

Background

The social, economic, and educational impact of head lice infestations is considerable. It is most commonly seen in school-aged children, and girls are more commonly affected than boys. New therapeutic options are now available that may help clinicians to keep ahead of lice.

Infestation

• Caused by the obligate ectoparasite Pediculus humanus capitis; can survive for 1–2 days away from the scalp.
• Transmission most commonly occurs through:
• Close physical contact, especially head-to-head contact
• Fomites, such as hats.
• Transfer is optimal when hairs are relatively stationary and parallel, i.e., while children are at rest.
• Eggs are glued to the hair close to the scalp in egg castings, or nits. Nits within 1cm of the scalp should be counted as a sign of active infestation.

Clinical Presentation

• Most common symptom is pruritus.
• Occurs due to sensitization to either louse salivary or fecal antigens.
• May be so intense that excoriations and secondary bacterial infection may occur.
• Diagnostic gold standard is finding a live louse or nymph on the scalp, or a viable egg attached to the hair. Microscopic examination of the nit may aid in this determination.
• Nits alone are not proof of active infection.
• Not finding a louse does not completely rule out infestation.
• Louse combs increase the diagnostic yield.

Treatment Options

Pediculicides: Neurotoxic Agents

• Includes permethrin, permethrin-based products, malathion, and lindane.
• Not recommended for children < 2 years of age. Off-label use based on clinical judgement.
• Avoid hair conditioner before applying; it may coat the hair and protect the lice and nits.

Permethrin-based Products

• OTC extracts of natural pyrethrins from chrysanthemums combined with piperonyl butoxide to increase stability and effect.
• Neurotoxic to lice, but not ovicidal; even after two treatments viable lice and eggs may remain.
• Contraindicated in patients allergic to ragweed, chrysanthemums, or other permethrin products.

Permethrin 1%

• Historically considered standard treatment; however issues of resistance have made it necessary to explore new alternatives.
• It is a poorly absorbed synthetic pyrethrin with pediculicidal and ovicidal activity.
• Leaves a residue on the hair and remains active for 2 weeks following application.
• Wash hair, rinse with water, towel dry, then apply to entire scalp and hair for 10 minutes and rinse out. Treat again 7-10 days later.

Malathion 0.5%

• Can be applied for 10 minutes or overnight and repeated in 1 week.
• Can cause stinging of the skin and eyes.
• Should be used with caution:
  • base is flammable.
  • may lead to respiratory depression if ingested (there are no reported cases).
• No significant resistance has been reported in the US.

Lindane 1% Lotion

• Second-line treatment to be used as an alternative when other treatments have failed.
• Has limited ovicidal activity; kills lice by causing CNS stimulation and respiratory paralysis.
• Higher side-effect potential including neurotoxicity and bone marrow suppression.
• Contraindicated in children < 2 years, pregnant women, and nursing mothers.

Oral Agent – Ivermectin

• An antihelminthic drug and effective pediculicide
• Suggested for off-label use in the treatment of head lice at a dosage of 200ìg/kg, to be repeated in 7-10 days.
• Possible neurotoxicity is a concern; safety and efficacy remain to be established.
• No resistance has been reported to date and it may be used after failure with topical pediculicides.
• May be useful for extensive infestations or infestations with multiple types of ectoparasites.
• Should not be used in children weighing < 15kg.

Non-neurotoxic Pediculicides

• Exoskeleton Integrity Dehydration Pediculicides
• This is new nonpesticide, nonprescription, behind-thecounter product containing isopropyl myristate 50% and ST-cyclomethicone 50% (Resultz™).
• Recently approved by Health Canada for the treatment of lice in persons aged 4 years and older.
• Works by dissolving the waxy exoskeleton that covers the lice.
• Apply first to dry hair, scalp, and the nape of the neck, leave in place for 10 minutes, then rinse. Repeat in 1 week.
• Phase II clinical trials document a higher success rate (no live lice) compared with traditional pediculicides (57% isopropyl myristate 50% and ST-cyclomethicone 50% vs. 22% with .33% pyrethrin + 4% piperonyl butoxide; 77.1% isopropyl myristate 50% and ST-cyclomethicone 50% vs. 20% with permethrin 1%). [Data on file – Altana Pharma.]
• Other phase II studies showed a 97% (28 of 29 patients) success rate.[Kaul N, et al. In vivo efficacy and safety of an experimental pediculicide rinse. Presented at: the 63rd Annual Meeting of the American Academy of Dermatology, New Orleans, Feb 2005.]
• Well tolerated with mild local erythema or pruritus being the main side-effect.

Dry-on Suffocation Based Pediculicide

• Originally marketed as Nuvo® Lotion; it was later discovered to be Cetaphil® Gentle Skin Cleanser.
• Reported 96% success rate when applied to the scalp, dried with a hair dryer (for ~30 minutes), and removed during the next day’s bath.[Pearlman DL. Pediatrics 114(3):e275-9 (2004 Sep).]
• Reviews found that the study did not use proper methods of diagnosing lice, was anecdotal, and was not a welldesigned, randomized control study.[Roberts RJ, et al. Lancet 365(9453):8-10 (2005 Jan); Burkhart CG, et al. J Am Acad Dermatol 54(4):721-2 (2006 Apr).]
• Given encouraging preliminary results, further study is warranted.

Mechanical

• Nit combing is labor intensive and somewhat painful; should not be used alone.
• Application of a 8% formic acid rinse or a 1:1 mixture of white vinegar and water followed by combing with a nit comb can aid in nit removal.
• The only treatment recommended for children < 2 years of age.

Environmental Interventions

• Decontaminate clothing, linen and towels by washing in hot water (60°C) or dry-cleaning.
• Treat combs and brushes with boiling water, alcohol, bleach, or soak in a disinfectant solution (e.g., 2% Lysol^®).
• Examine all household members and close contacts and treat concurrently if infested.
• Notify the school.
• Treat bedmates prophylactically.

Treatment Categories

Treatment Failures and Resistance

Resistance to permethrin and lindane is common in populations where these pediculicides have been heavily used. Treatment failures can also be a result of reinfestation from:

• an untreated classmate
• an inadequate quantity of pediculicide applied
• the improper duration of product application.

A second treatment of the prescribed pediculicide should be administered 7-10 days after the start of treatment to kill all active stages of the louse. Resistance should be suspected if live lice are still present 2-3 days after the second application of a product has been used correctly and no other cause for failure can be identified.

• If lice are present after 2 correctly applied treatments, resistance is certain.
• Resistant infestations should be treated with an agent from a different class of pediculicides

Conclusion

Lice have developed resistance to some pediculicides and it is expected that with ongoing use, these pediculicides will probably become less effective. These products can still be used effectively to treat nonresistant lice. New products are now available in Canada that may prove to be equal to or more effective/safe than the standard neurotoxic pediculicides, while
at the same time minimize the problem of treatment-resistant lice.

1. University of British Columbia Student Health Services, Vancouver, Canada
2. Department of Dermatology and Skin Science, University of British Columbia,
and The Pediatric Allergy Dermatology Centre (PADC), Vancouver, Canada

ABSTRACT

Pediculosis capitis, or head lice, is a world-wide public health concern affecting persons of all ages and socioeconomic backgrounds. It is caused by Pediculus humanus capitis, an obligate ectoparasite that lives on human hair and feeds on the blood from the skin. Upon diagnosis, treatment should be initiated, since established infestations with head lice generally do not spontaneously resolve. Chemical pediculicides are currently the standard treatment, however, issues of resistance have made it necessary to explore new alternatives. If an infestation is resistant to these drugs, then the physician should consider treating with an agent from a different class of pediculicides or, potentially, with newer nonpediculicides.

Key Words:
pediculosis capitis, head lice, pediculicide

In the US, the number of head lice infestations annually is estimated between 6–12 million among children 3–12 years of age.¹ The social, economic and educational impact of head lice infestations is considerable. In the US, the total direct costs for treatment and indirect costs for lost wages, educational programs, and school and nursing home monitoring programs have been estimated at more than $1 billion annually.²

Infestation is most common in school-aged children with girls being more commonly affected than boys. African-American children are less often affected; this variation is thought to be the result of differences in the hair shaft structure, which may be oval shaped and thus more difficult for a louse to grasp.¹ Transmission of head lice most commonly occurs through close physical contact, especially head-to-head contact, but fomites, such as hats also play a role. Louse transfer has been found to be optimal when hairs are relatively stationary and parallel, suggesting that louse transmission is more likely to occur while children are at rest, than during periods of vigorous play.³

Head lice infestation is caused by the obligate ectoparasite Pediculus humanus capitis, a wingless, elongated, dorsoventrally flattened insect. The adult louse feeds 4–5 times/day and can normally only survive for 1–2 days away from the scalp. Eggs are glued to the hair in egg castings, or nits, close to the scalp and can survive up to 10 days away from the human host. Lice typically lay nits within 1–2mm of the scalp and for practical purposes, nits within 1cm of the scalp should be counted as a sign of active infestation.⁴

Clinical Presentation

Although some children with infestation are asymptomatic, the most common symptom is pruritus, which occurs due to sensitization to either louse salivary or fecal antigens and may be so intense that excoriations and secondary bacterial infection may occur.⁵

Many children with an active infestation will, on exam, have nits attached to their hair and some live lice on their scalp. The diagnostic gold standard for head lice is finding a live louse or nymph on the scalp or a viable egg attached to the hair.⁵ Nits alone are not proof of active infection because some of these represent hatched empty shell casings or nonviable eggs that may retain a viable appearance for weeks after death. Microscopic examination of the nit, or use of a hand lens, may aid in this determination.⁴ Since lice move rapidly, not finding a louse does not completely rule out infestation. The use of louse combs increases the diagnostic yield.³ If head lice is diagnosed, then it should be treated, since established infestations, in general, do not spontaneously resolve.

Treatment

The ideal treatment agent for lice would be free of harmful chemicals, readily available without a prescription, easy to use, and inexpensive.⁵ Chemical pediculicides are currently the standard treatment.

Prior to the emergence of resistance, the treatment of choice in North America was permethrin 1% due to its safety and efficacy. Unfortunately resistance to permethrin and lindane is common in populations where these pediculicides have been heavily used.³ To illustrate this, the insecticidal activity of pyrethroids in the mid 1980s was 100%, but by 2000 it had decreased to only 28%.⁶ Conversely Meinking, et al., in a recent study, showed 1% lindane was the slowest and least effective pediculicide with no lice eradicated after 10 minutes (the recommended application time), and killing only 17% of lice after 3 hours.⁷ Malathion (Ovide^®, Taro Pharmaceuticals), which had not been used extensively in the US, has performed well in permethrin-resistant populations.³ Lice resistance to both pyrethrin and malathion has been documented in the UK (Downs, et al. showed a 64% failure rate for malathion).⁸ The pattern of resistance in an area generally follows the pattern of pediculicide use, and this geographic variation in sensitivities further reinforces the belief that lice adapt to toxins and develop resistance with ongoing exposure.

Treatment Failures

While treatment failures may be due to drug resistance, it is important to recognize many treatment failures are a result of reinfestation from an untreated classmate, inadequate quantity of pediculicide applied, or improper duration of product application.4 A recent paper suggested that a second treatment of the prescribed standard pediculicides (except permethrin) should be administered ideally 10 days after the start of treatment to kill all active stages of the louse.⁹ However, in practice many physicians retreat in 7 days instead of 10. Resistance should be suspected after the second treatment if live lice are still present 2-3 days after a product has been used correctly and no other cause for failure can be identified.1 If lice are present after 2 correctly applied treatments, resistance is certain.¹ Resistant infestations should be treated with an agent from a different class of pediculicides or with newer nonpediculicide agents.

Since permethrin resistance may be a relative phenomenon, some clinicians will use higher concentrations and longer durations of contact in an attempt to overcome this resistance. Whether increasing the permethrin concentration from 1% to 5% and leaving it on overnight affects the cure rate is unclear. Certainly this pattern of treatment may cause a higher rate of skin irritation, but longer contact with the same products is already used with other ectoparasites, such as scabies.

‘No nit’ policies exclude children from school unnecessarily and are not recommended.⁴ The presence of nits alone should not be the basis for exclusion of children from school. The child should be allowed to return to school or child care facilities after proper treatment.⁵

Myths and Facts

Myths about head lice are abundant and belief in these myths is often why treatments are not used properly and why people believe their lice treatment has failed. (See Table 1.)

Standard Pediculicides: Neurotoxic Agents

These agents are historically considered the standard treatment and have been the most effective treatment for head lice. This category of pediculicides is not recommended for children under 2 years of age and off-label use of these products for patients in this age range is based on clinical judgment.⁵ These products should be applied to the entire scalp. Because hair conditioner may coat the hair and protect the lice and nits, it should be avoided before product application.⁷

Permethrin

Permethrin 1% (Nix^®) is a poorly absorbed synthetic pyrethrin with pediculicidal and ovicidal activity. It blocks sodium channel repolarization of the louse neuron resulting in respiratory paralysis and death. By leaving a residue on the hair, it remains active for 2 weeks following application.⁵ After washing hair, rinsing with water, and towel drying, it is applied to the scalp and hair for 10 minutes and then rinsed out. To ensure a cure, many practitioners recommend a second treatment approximately 1 week later as any eggs not killed by first treatment will be hatching.

Permethrin-based Products

Permethrin-based products include over-the-counter (OTC) extracts of natural pyrethrins from chrysanthemums combined with piperonyl butoxide to increase stability and effect. These products are neurotoxic to lice but not ovicidal and even after two treatments viable lice and eggs may remain. These products are contraindicated in patients who are allergic to ragweed, chrysanthemums, or other permethrin products.⁵

Malathion

Malathion is an organophosphate cholinesterase inhibitor that causes respiratory paralysis of the louse. It is a fast acting pediculicide that presently has the highest ovicidal activity. It binds to the sulfur atoms of the hair, accounting for its residual effect. Malathion 0.5% can be applied for 10 minutes or overnight and repeated in 1 week. It has an unappealing odor and can cause stinging of the skin and eyes.⁵ This product should be used with caution, as its base is flammable and may lead to respiratory depression if ingested (although there are no reported cases).⁴ Currently significant resistance to this agent has not been reported in the US, but may occur with ongoing use as seen in other countries.⁸

Lindane

Lindane (gamma benzene hexachloride) 1% lotion is pediculicidal but it has limited ovicidal activity. This organochloride kills lice by causing CNS stimulation and respiratory paralysis. Given lindane’s increased side-effect potential including neurotoxicity and bone marrow suppression, it is considered a second-line treatment.5 Lindane remains on the market as an alternative when other treatments have failed. It is contraindicated in children under 2 years, pregnant women, and nursing mothers.

Oral Agents

Ivermectin

Ivermectin, an antihelminthic drug, has been suggested for off-label use in the treatment of head lice at a dosage of 200ìg/kg, repeated in 7-10 days to kill newly hatched nymphs.11 It is an effective pediculicide and the mechanism of action is thought to be on the symbiotic gram-negative bacteria that are required to digest blood. With the concern of possible neurotoxicity, the safety and efficacy of this agent for head lice remains to be established.³ No resistance has been reported to date and it may be used after failure with topical pediculicides. Treatment with this agent may benefit patients with extensive infestations or infestations with multiple types of ectoparasites.³ Oral ivermectin should not be used in children weighing less than 15kg.⁴ Topical ivermectin holds some promise but warrants further study.³

TMP/SMX

Oral TMP/SMX has been shown to be effective in small studies of off-label use.5 It presumably works by destroying the gut flora of the louse, thereby interfering with its ability to synthesize vitamin B and ultimately causing death.5 Combination therapy with topical agents may improve it’s efficacy.

Non-neurotoxic Agents

Exoskeleton Integrity Dehydration Pediculicides

A new nonpesticide product containing isopropyl myristate 50% and ST-cyclomethicone 50% (Resultz™, Altana) works by dissolving the waxy exoskeleton of the louse, dehydrating them and eventually leading to their death. The first application is applied to dry hair, the scalp, and the nape of the neck; it is left in place for 10 minutes and then rinsed. A second application, 1 week later is recommended.

Based on safety and efficacy data, Health Canada has recently approved this nonprescription behind the counter product for the treatment of lice in persons aged 4 years and older. Phase II clinical trials document a higher success rate (no live lice) when compared with traditional pediculicides (57% Resultz™ vs. 22% with RID^®; 77.1% Resultz™ vs. 20% with permethrin 1%).¹⁷ Other Phase II studies have documented a 97% (28 of 29 patients) success rate.¹⁶ In studies to date, the product was well tolerated with mild local erythema or pruritus being the main side-effect (8 of 29 patients).¹⁶ Phase III clinical trials are pending. Isopropropyl myristate is a water-insoluble organic ester used as an emulsifier and emollient in low concentrations in cosmetic products such as oils, creams, lotions, makeup, lipstick, deodorants, sun screens, hair products, and nail lacquer removers.¹⁸

Dry-on Suffocation-Based Pediculicide

Nuvo^® Lotion, or dry-on suffocation-based pediculicide (DSP) (later found to be Cetaphil^® Gentle Skin Cleanser) was reported to have success rate of 96% when applied to the scalp, dried with a hair dryer (for approximately 30 minutes), and removed during the next day’s bath.¹² It was reported to work by suffocating the louses’ spiracles or breathing holes, causing death by suffocation. As reviewed in The Lancet13 and other sources,^14,15 the study did not use proper methods of diagnosing lice, was anecdotal, and was not a well-designed randomized control study. Nevertheless, the concept is novel and there may be a significant beneficial effect; therefore further studies are warranted.

Nit Agents

Further knowledge of the nit sheath, the glue by which the egg is attached to human hair, or the nit laying process may lead to the production of future treatment agents.¹⁹

Mechanical Removal

Mechanical nit removal as a treatment modality is not an appropriate method of lice eradication when used alone.20 Some authors believe that mechanical removal of nits after treatment with a pediculicide remains an important adjunct.³ Application of an 8% formic acid rinse or a 1:1 mixture of white vinegar and water followed by combing with a nit comb can aid in the removal of nits. Nit combing is the only treatment recommended for children < 2 years of age. It is labor intensive and somewhat painful.²¹

Environmental Interventions

Clothing, linen and towels should be decontaminated by hot water washing (60°C) or dry-cleaned. Combs and brushes should be treated with boiling water, alcohol, bleach, or soaked in a disinfectant solution (for example 2% Lysol^®).

All household members and close contacts should be examined and treated concurrently if infested; and the school should be notified. Bedmates should be treated prophylactically. Furniture disinfection is unnecessary since head lice generally die within 1–2 days when separated from a person.⁵

Alternative Treatments

Naturopathic products including herbal shampoos, occlusive agents (e.g., mayonnaise, margarine, and olive oil), kerosene or gasoline are largely unproven or ineffective.22 There is no evidence that the occlusive products suffocate lice and they have no pediculicidal or ovicidal effects.²² Kerosene or gasoline should never be used due to flammability and extreme hazard. Another “natural” remedy is Chick-Chack^®, containing coconut oil, anise oil, and ylang ylang oil.³ Published data is sparse and caution should be advised until more data is available.

Conclusion

Lice have developed resistance to some pediculicides and it is expected that with ongoing use these pediculicides will probably become less effective. These products can still be used effectively to treat nonresistant lice. Resistance should be suspected if live lice are still present 2–3 days after a product has been used correctly and no other cause for treatment failure can be identified. If lice are present after 2 correctly applied treatments, resistance is almost certain. Resistant infections should be treated with an agent from a different class of pediculicides or with newer non-neurotoxic agents. New products are presently in the process of being developed and tested. Over time these products may prove to be equal to or more effective/safe than the standard neurotoxic pediculicides, while at the same time minimize the problem of treatment resistant lice.

References

1. Hansen RC. Overview: the state of head lice management and control. Am J Manag Care 10(9 Suppl):S260-3 (2004 Sep).
2. Hansen RC, O’Haver J. Economic considerations associated with Pediculus humanus capitis infestation. Clin Pediatr 43(6):523-7 (2004 Jul-Aug).
3. Elston DM. Drugs used in the treatment of pediculosis. J Drugs Dermatol 4(2):207-11 (2005 Mar-Apr).
4. Frankowski BL. American Academy of Pediatrics guidelines for the prevention and treatment of head lice infestation. Am J Manag Care 10(9 Suppl):S269-72 (2004 Sep).
5. Leung AK, Fong JH, Pinto-Rojas A. Pediculosis capitis. J Pediatr Health Care 19(6):369-73 (2005 Nov-Dec).
6. Burkhart CG, Burkhart CN. Clinical evidence of lice resistance to over-the-counter products. J Cutan Med Surg 4(4):199-201 (2000 Oct).
7. Meinking TL, Serrano L, Hard B, et al. Comparative in vitro pediculicidal efficacy of treatments in a resistant head lice population in the United States. Arch Dermatol 138(2):220-4 (2002 Feb).
8. Downs AM, Stafford KA, Harvey I, Coles GC. Evidence for double resistance to permethrin and malathion in head lice. Br J Dermatol 141(3):508-11 (1999 Sep).
9. Mumcuoglu KY. Effective treatment of head louse with pediculicides. J Drugs Dermatol 5(5):451-2 (2006 May).
10. Hong CH. Treatment of head lice. Skin Therapy Lett – Pharm Ed 1(2):4-5 (2006 Sep-Oct).
11. Mazurek CM, Lee NP. How to manage head lice. West J of Med 172(5):342-5 (2000 May).
12. Pearlman DL. A simple treatment for head lice: dry-on, suffocation-based pediculicide. Pediatrics 114(3):e275-9 (2004 Sep).
13. Roberts RJ, Burgess IF. New head lice treatments: hope or hype? Lancet 365(9453):8-10 (2005 Jan).
14. Burkhart CG, Burkhart CN. Asphyxiation of lice with topical agents, not a reality…yet. J Am Acad Dermatol 54(4):721-2 (2006 Apr).
15. “Special” formula for head lice treatment-not so special, after all. Child Health Alert. 24:4 (2006).
16. Kaul N, Paulma KG, Maric A, et al. In vivo efficacy and safety of an experimental pediculicide rinse. Presented at: the 63rd Annual Meeting of the American Academy of Dermatology, New Orleans, Feb 2005.
17. Data on file – Altana Pharma.
18. National library of medicine/ NIH specialized Information Services. Household products database [online]. Available from: http://householdproducts.nlm.nih.gov/cgi-bin/household/brands?tbl=chem&id=94; accessed 2006 Nov 22.
19. Burkhart CN, Burkhart CG. Head lice: scientific assessment of the nit sheath with clinical ramifications and therapeutic options. J Am Acad Dermatol 53(1):129-33 (2005 Jul).
20. Meinking TL. Clinical update on resistance and treatment of pediculosis capitis. Am J Manag Care 10(9 Suppl):S264-8 (2004 Sep).
21. Roberts, RJ. Clinical practice. Head lice. New Engl J Med 346(21):1645-50 (2002 May).
22. West DP. Head lice treatment costs and the impact on managed care. Am J Manag Care 10(9 Suppl):S277-82 (2004 Sep).

Department of Dermatology and Skin Science, University of British Columbia,
Vancouver, Canada

ABSTRACT

Common diaper dermatitis is an irritant contact diaper dermatitis (IDD) created by the combined influence of moisture, warmth, urine, feces, friction, and secondary infection. It is difficult to completely eradicate these predisposing factors in a diapered child. Thus, IDD presents an ongoing therapeutic challenge for parents, family physicians, pediatricians, and dermatologists. This article will focus on practical management strategies for IDD.

Key Words:
diaper dermatitis, IDD

IDD is a common inflammatory eruption of the skin in the diaper area created by the presence of moisture, warmth, urine, feces, and friction, and is seen in 25% of children wearing diapers.¹

Pathogenesis

Four key factors contribute to the development of IDD:²

Wetness

• Wet diapers result in excessive hydration and maceration of the stratum corneum3 leading to impaired barrier function, enhanced epidermal penetration by irritants and microbes, and susceptibility to frictional trauma.⁴

Friction

• IDD is most commonly distributed in areas with the greatest skin-to-diaper contact.⁵
• Mechanical trauma disrupts the macerated stratum corneum, exacerbating barrier dysfunction.

Urine and feces

• Candida albicans (C. albicans) and, less commonly, Staphylococcus aureus (S. aureus) infections are associated with IDD.⁸
• The warm, humid, and high pH environment in the diaper provides the ideal milieu for microbial proliferation.
• Innate antimicrobial microflora cannot survive in a high pH environment.⁹
• There is a positive correlation between the clinical severity of IDD and the presence and level of C. albicans in the diaper, mouth, and anus of infants.⁸

Microorganisms

• The interaction of urine and feces is key to the pathogenesis of IDD. Bacterial ureases in the stool degrade the urea that is found in urine, releasing ammonia and increasing local pH.⁶
• Fecal lipases and proteases are activated by the increased pH. They cause skin irritation and disruption of the epidermal barrier.⁷
• Ammonia does not irritate intact skin; it is thought to mediate irritation by contributing to the high local pH.⁶

Clinical Features

IDD initially presents with localized asymptomatic erythema, and can progress to widespread painful, confluent erythema with maceration, erosions, and frank ulceration.10 IDD commonly spares the skin folds, and affects the convex skin surfaces in close contact with the diaper including the buttocks, genitalia, lower abdomen, and upper thighs. IDD complicated by Candida presents with beefy red intertriginous plaques and satellite papules and pustules in the diaper area. IDD complicated by S. aureus appears impetiginized, with erosions, honey-colored crust, and lymphadenopathy.

Granuloma gluteale infantum and Jacquet erosive diaper dermatitis are distinctive, severe variants of IDD. Granuloma gluteale infantum presents in the setting of IDD with violaceous papules and nodules on the buttocks and in the groin. The pathogenesis of granuloma gluteale infantum is not clear. Potential risk factors include treatment with topical steroids,¹¹ candida infection, and occlusive plastic diaper covers.¹² Granuloma gluteale infantum follows a self-limited course, resolving in weeks to months, often with residual scarring.^5,11 The presence of punched-out erosions or ulcerations with heaped-up borders characterizes Jacquet erosive diaper dermatitis. This uncommon and severe presentation of IDD typically occurs in the context of frequent liquid stools, poor hygiene, infrequent diaper changes, or occlusive plastic diapers.¹²

It is imperative to consider other conditions that may occur in the diaper area. Several excellent references are available that outline the differential diagnosis of IDD.^5,13 Please see Table 1 for a review of the clinical features of relevant diaper dermatoses.

Risk Factors

Fecal incontinence and diarrhea are risk factors for severe IDD because of prolonged and frequent skin contact with stool. Examples of at-risk children include those with Hirschsprung’s disease, fecal impaction and overflow, and anogenital malformations.14 Fecal proteases and lipases are also upregulated when gastrointestinal transit time is low.⁹ Increased bile acids in stool, seen in short gut syndrome and conjugated hyperbilirubinemia, also increase protease activity.¹² Children with atopic dermatitis are prone to IDD because of their sensitivity to irritants and a greater susceptibility to secondary infection.

Treatment

Diapers

The continuous use of diapers is at the root of IDD. Maximizing “diaper-free” time is a widely recommended preventative strategy, but is not very practical. Frequent diaper changes are essential for maintaining dryness and keeping urine and feces separated. Diapers should be changed as soon as they are wet or soiled, at least every 3–4 hours and more frequently in the neonate due to increased skin fragility.¹⁵ Parents should forego tight-fitting diapers and consider a diaper slightly larger than the infant to minimize the contact between skin and urine or feces.⁵ Common IDD should resolve when children become toilet trained.

The advent of disposable diapers and the ongoing development of new diaper technology has radically changed the face of IDD. Early cellulose-core containing disposable diapers were dramatically improved by the addition of cross-linked sodium polyacrylate polymers to the diaper core.^10,16,17 These polymers, also called absorbent gelling materials, bind water in a gel matrix when hydrated.^16,17 This gel effectively traps moisture away from the skin surface. It controls pH through its buffering capacity, and by separating urine from feces.¹⁷ These diapers are referred to as superabsorbent diapers.¹⁶ In a study of 1,614 infants, superabsorbent diapers were associated with reduced skin wetness, superior
pH control, and less diaper dermatitis compared with cellulose-core disposable and cloth diapers.¹⁷ Originally, these diapers were developed with an impenetrable backsheet (outer cover) to prevent leaks, but this led to increased humidity and skin maceration. A “breathable” diaper was subsequently developed with a backsheet that is permeable to air and vapor but still impenetrable to leaks.16 This backsheet is readily identified by its cloth-like, rather than plastic, texture. The “breathable” superabsorbent diaper has been shown to reduce the prevalence of severe IDD by up to 50%.¹⁰ Nearly all commercially available disposable diapers in North America now use polyacrylate gel-core technology, and many use the breathable backsheet (e.g., Pampers^®, Procter & Gamble; Huggies^®, Kimberly-Clark). A novel diaper has recently been developed that transfers a petrolatum and zinc oxide-based formula to the child’s skin.¹⁸ In a double-blinded, randomized trial, infants using this diaper had consistently less skin erythema and diaper rash compared with those using a superabsorbent diaper alone over a 4-week period of use.¹ Cloth diapers are not recommended for patients with IDD. They increase skin wetness, promote mixing of urine and feces, and are associated with Jacquet erosive diaper dermatitis.¹²

Barrier

Application of a suitable barrier preparation is the cornerstone of prevention and treatment of IDD. There is a notable absence of controlled trials to support and guide the use of barrier preparations for IDD. Anecdotal evidence is abundant and suggests a barrier preparation should be applied to the diaper area after every diaper change and bath. A suitable barrier preparation should minimize transepidermal water loss (TEWL) and decrease permeability to irritants.⁹ The barrier corrects these deficits by forming a lipid barrier over the skin surface, or by penetrating the stratum corneum and assuming the role of endogenous intercellular lipids.^5,19 The barrier also minimizes cutaneous friction. The barrier must be lipid-rich, long-lasting and adherent to the macerated and eroded diapered skin.

Pastes are the most hardy and desirable barriers, followed by ointments. Ointments are superior to creams and lotions, which are poorly adherent, minimally occlusive, and contain preservatives. Diaper pastes are tenacious semisolid compounds containing a high
proportion (usually >10%)9 of a fine powder such as zinc oxide, titanium dioxide, and starch or talc.²⁰ Pastes should be applied thickly, like “icing on a cake”, and can be covered by petroleum jelly to avoid sticking to the diaper.¹⁴ Products containing fragrance, preservatives, and other ingredients with irritant or allergic potential should be avoided. Products containing boric acid, camphor, phenol, and salicylates should be avoided due to potential systemic toxicity.²¹ The local ostomy nurse may also be a valuable resource in identifying suitable barrier preparations in severe IDD.

Cleansing

Children predisposed to IDD should be bathed daily in a lukewarm bath using an irritant-free and fragrance free soap or cleanser followed by liberal application of a barrier preparation to the diaper area. The diaper area should be cleaned gently and dried by patting with a towel to avoid any undue friction. Aggressive wiping at diaper changes should be avoided. Residual adherent barrier paste does not need to be wiped off along with the urine and stool at each diaper change. Mineral oil can help facilitate paste removal, if required.^5,14

It is a commonly held belief that baby wipes contribute to IDD; however an investigator-blinded, parallelcomparison study of 102 infants found no difference between skin cleaned with an alcohol-free, nonwoven disposable wipe, and skin cleaned with water and a cleanser.²² Moreover, skin cleaned with wipes had statistically better rash scores in the intertriginous areas, suggesting that wipes may help parents access hardto- reach areas. These wipes were found to be safe and well tolerated in infants with atopic dermatitis. Baby wipes can cause an allergic contact hand dermatitis in caregivers, in a “grip-like” distribution.²³ It is prudent to choose wipes without fragrance and preservatives to avoid allergic sensitization.

Infection

Candida infection is often associated with moderatesevere cases of IDD. C. albicans is present in the mouth, inguinal and perianal skin more frequently in patients with IDD.⁸ The azoles, nystatin, and ciclopirox are all appropriate topical anticandidal agents,^5,24 but few well-designed comparative trials are available to guide clinical practice. Twice-daily
application is recommended until resolution. In a National Ambulatory Medical Care Survey (NAMCS), more than 200,000 visits for diaper dermatitis in the US were reviewed; nystatin and clotrimazole were the most commonly prescribed topical antifungals (27% and 16% respectively).¹ A prospective, randomized study compared topical nystatin with mupirocin in the treatment of IDD complicated by C. albicans infection. Treatment with both agents resulted in mycological cure; however, resolution of IDD was observed in all patients treated with mupirocin compared with only 30% treated with nystatin.²⁵ Application of miconazole nitrate 0.25% in a zinc oxide and petrolatum base has demonstrated efficacy and safety in vehicle-controlled, randomized, double-blinded trials.^26,27 In an open trial, ciclopirox 0.77% topical suspension demonstrated significant improvement in rash severity and superior mycological cure by 7 days in patients with IDD and C. albicans infection.²⁸ There is little evidence to support the addition of an oral antifungal to topical therapy in IDD.²⁹ Patients with concomitant oral thrush, however, may benefit from a course of systemic antifungal therapy.⁵

Corticosteroids

A short course of a mild topical corticosteroid is frequently necessary in moderate-to-severe IDD. Hydrocortisone 1% ointment can be applied to affected areas twice daily for a limited duration. Mid-to-high potency corticosteroids should never be used in the diaper area. The NAMCS documented a surprisingly high rate of moderate-to-high potency halogenated topical corticosteroid use in IDD. Triamcinolone acetonide or betamethasone dipropionate use, either alone or in combination with antifungals, was documented in a staggering 24.3% of visits for diaper dermatitis.1 Atrophy, systemic absorption, candidiasis, and granuloma gluteale infantum are all associated with mid-to-high potency corticosteroid use in the diaper area. The topical calcineurin inhibitors, tacrolimus and pimecrolimus, have not been studied for the treatment of IDD. These agents have been studied for efficacy and safety as a steroid-sparing treatment for atopic dermatitis in infants < 2 years old.³⁰ Although they are not approved for use in this age group, they may be a useful off-label alternative for IDD in the appropriate clinical setting.

Other Agents

A number of other agents have been reported to be efficacious in the treatment of IDD. A recent pilot study found clinical and mycological benefits using a 1:1:1 mixture of honey: olive oil: beeswax to treat IDD.³¹ Eosin, an orange-red dye derived from coal tar, is a common agent used for IDD in Europe. It was found to have a greater rate of clearance of IDD within 5 days compared with zinc oxide and a moderate-potency topical corticosteroid ointment.³² In a randomized, vehicle-controlled study, topical vitamin A cream did not improve the outcome of IDD.³³

Conclusion

IDD is a common dermatosis afflicting diapered children. It is caused by wetness, friction, urine, stool, and microorganisms. A proactive approach targeting predisposing factors is the best defence against IDD.

References

1. Ward DB, Fleischer AB Jr, Feldman SR, Krowchuk DP. Characterization of diaper dermatitis in the United States. Arch Pediatr Adolesc Med. 154(9):943-6 (2000 Sep).
2. Atherton DJ. The aetiology and management of irritant diaper dermatitis. J Eur Acad Dermatol Venereol 15 Suppl 1:1-4 (2001).
3. Willis I. The effects of prolonged water exposure on human skin. J Invest Dermatol 60(3):166-71 (1973 Mar).
4. Zimmerer RE, Lawson KD, Calvert CJ. The effects of wearing diapers on skin. Pediatr Dermatol 3(2):95-101 (1986 Feb).
5. Shin HT. Diaper dermatitis that does not quit. Dermatol Ther 18(2):124-35 (2005 Mar-Apr).
6. Berg RW, Buckingham KW, Stewart RL. Etiologic factors in diaper dermatitis: the role of urine. Pediatr Dermatol 3(2):102-6 (1986 Feb).
7. Andersen PH, Bucher AP, Saeed I, Lee PC, Davis JA, Maibach HI. Faecal enzymes: in vivo human skin irritation. Contact Dermatitis 30(3):152-8 (1994 Mar).
8. Ferrazzini G, Kaiser RR, Hirsig Cheng SK, et al. Microbiological aspects of diaper dermatitis. Dermatology 206(2):136-41 (2003).
9. Atherton DJ. A review of the pathophysiology, prevention and treatment of irritant diaper dermatitis. Curr Med Res Opin 20(5):645-9 (2004 May).
10. Akin F, Spraker M, Aly R, Leyden J, Raynor W, Landin W. Effects of breathable disposable diapers: reduced prevalence of Candida and common diaper dermatitis. Pediatr Dermatol 18(4):282-90 (2001 Jul-Aug).
11. Bluestein J, Furner BB, Phillips D. Granuloma gluteale infantum: case report and review of the literature. Pediatr Dermatol 7(3):196-8 (1990 Sep).
12. Fiorillo L. Therapy of pediatric genital diseases. Dermatol Ther 17(1):117-28 (2004).
13. Kazaks EL, Lane AT. Diaper dermatitis. Pediatr Clin North Am 47(4):909-19 (2000 Aug).
14. Borkowski S. Diaper rash care and management. Pediatr Nurs 30(6):467-70 (2004 Nov-Dec).
15. Lane AT, Rehder PA, Helm K. Evaluations of diapers containing absorbent gelling material with conventional disposable diapers in newborn infants. Am J Dis Child 144(3):315-8 (1990 Mar).
16. Odio M, Friedlander SF. Diaper dermatitis and advances in diaper technology. Curr Opin Pediatr 12(4):342-6 (2000 Aug).
17. Campbell RL, Seymour JL, Stone LC, Milligan MC. Clinical studies with disposable diapers containing absorbent gelling materials: evaluation of effects on infant skin condition. J Am Acad Dermatol 17(6):978-87 (1987 Dec).
18. Baldwin S, Odio MR, Haines SL, O’Connor RJ, Englehart JS, Lane AT. Skin benefits from continuous topical administration of a zinc oxide/petrolatum formulation by a novel disposable diaper. J Eur Acad Dermatol Venereol 15 Suppl 1:5-11 (2001 Sep).
19. Clark C, Hoare C. Making the most of emollients. Pharm J 266:227-229 (2001).
20. Juch RD, Rufli T, Surber C. Pastes: what do they contain? How do they work? Dermatology 189(4):373-7 (1994).
21. Farrington E. Diaper dermatitis. Pediatr Nurs 18(1):81-2 (1992 Jan-Feb).
22. Ehretsmann C, Schaefer P, Adam R. Cutaneous tolerance of baby wipes by infants with atopic dermatitis, and comparison of the mildness of baby wipe and water in infant skin. J Eur Acad Dermatol Venereol 15 Suppl 1:16-21 (2001 Sep).
23. Guin JD, Kincannon J, Church FL. Baby-wipe dermatitis: preservative-induced hand eczema in parents and persons using moist towelettes. Am J Contact Dermat 12(4):189-92 (2001 Dec).
24. Gupta AK, Skinner AR. Management of diaper dermatitis. Int J Dermatol 43(11):830-4 (2004 Nov).
25. de Wet PM, Rode H, van Dyk A, Millar AJ. Perianal
26. candidosis—a comparative study with mupirocin and nystatin. Int J Dermatol 38(8):618-22 (1999 Aug).
27. 26. Concannon P, Gisoldi E, Phillips S, Grossman R. Diaper dermatitis: a therapeutic dilemma. Results of a double-blind placebo controlled trial of miconazole nitrate 0.25%. Pediatr Dermatol 18(2):149-55 (2001 Mar-Apr).
28. Spraker MK, Gisoldi EM, Siegfried EC, et al. Topical miconazole nitrate ointment in the treatment of diaper dermatitis complicated by candidiasis. Cutis 77(2):113-20 (2006 Feb).
29. Gallup E, Plott T, Ciclopirox TS Investigators. A multicenter, open-label study to assess the safety and efficacy of ciclopirox topical suspension 0.77% in the treatment of diaper dermatitis due to Candida albicans. J Drugs Dermatol 4(1):29-34 (2005 Jan- Feb).
30. Hoppe JE. Treatment of oropharyngeal candidiasis and candidal diaper dermatitis in neonates and infants: review and reappraisal. Pediatr Infect Dis J 16(9):885-94 (1997 Sep).
31. Patel RR, Vander Straten MR, Korman NJ. The safety and efficacy of tacrolimus therapy in patients younger than 2 years with atopic dermatitis. Arch Dermatol 139(9):1184-6 (2003 Sep).
32. Al-Waili NS. Clinical and mycological benefits of topical application of honey, olive oil and beeswax in diaper dermatitis. Clin Microbiol Infect 11(2):160- 3 (2005 Feb).
33. Arad A, Mimouni D, Ben-Amitai D, Zeharia A, Mimouni M. Efficacy of topical application of eosin compared with zinc oxide paste and corticosteroid cream for diaper dermatitis. Dermatology 199(4):319-22 (1999).
34. Bosch-Banyeras JM, Catala M, Mas P, Simon JL, Puig A. Diaper dermatitis. Value of vitamin A topically applied. Clin Pediatr (Phila) 27(9):448-50 (1988 Sep).

Faculty of Medicine, University of British Columbia, Vancouver, Canada

Diagnostic Features of Eczema or Atopic Dermatitis (AD)

Diagnostic Features of Eczema or Atopic Dermatitis (AD): a chronic relapsing condition in patients with a personal or family history of atopy. Usually starts before the age of 2 years and usually improves or resolves in older children and adults.

• Itching must be present to make the diagnosis
• Dry Skin is always present
• Typical Rash Location varies with age of patient. Infants: face usually involved. Diaper area and axilla usually clear. Extensor arms and legs involved due to friction from crawling. Children 4-10 years: flexures, sides of the neck, earlobes.
• Inflammed Skin usually seen
• Secondary Infection – Staphylococcus aureus very common, molluscum and herpes infections often more extensive

Treatment: Self-help and Medical Treatments

1. Patient Self-help – Patients may not improve if triggers are not removed

Aggravating/Trigger Factors to be Avoided

• Skin irritants such as soap, bubble bath, detergents, fabric softeners and perfumed products.
• Frequent bathing, especially if not followed by moisturizers. Sweating may exacerbate pruritus.
• Skin infection will tend to promote AD
• Food allergies can play a role in a small percentage of young patients with AD (e.g. eggs, milk, nuts, peanuts, fish, shellfish,
• wheat, and soy account for over 90% of food allergies)
• Environmental allergens such as house dust mites

Self-Help
1. Use a mild cleanser; 2. Moisturize often; 3. Hydrocortisone; 4. Cool bathing; 5. Use perfume free products; 6. Oral antihistamines; 7. Avoid triggers

Mild Cleansers

• Mild soap or nonsoap cleanser like Spectrojel®, Spectroderm®, Cetaphil®, plain white Dove®
• Emulsifying ointment USP (ask pharmacist)

Moisturizers
Use at least 250mg of cream/ week. Must be thick like butter or greasy like petroleum (e.g., Vaseline® Petroleum Jelly, Aquaphor® ointment, Creamy Vaseline®, 25% water in Hydrophilic Petrolatum, Aqueous cream, Aveeno® cream, unscented cold cream, Eucerin® cream, Cetaphil® cream, Cliniderm® cream)

2. Medical Treatment

Relief and suppression of eczema flares check list:

• Itch Relief – Dry Skin Therapy – Inflammation Suppression
• with anti-inflammatories
• Infection Control

Itch Relief
Oral-sedating antihistamines at bedtime. Hydroxyzine, Benadryl®, start at low dose and increase as tolerated. Moisturize and use topical anti-inflammatory. Wet compresses using gauze or face cloth dipped in tepid water, rung out and then laid on oozing skin is soothing.

Long-term Control by Preventing New Flares

Control of a flare may be easier than motivating a patient to continue intermittent use of an anti-inflammatory or to regularly moisturize the skin and avoid triggers. Using anti inflammatory topicals at the first signs and symptoms can minimize the use of medication and give smoother control of the disease.

Dry Skin

Frequent moisturizing especially within 2-5 minutes after bathing and when skin is wet. Most patients under moisturize. Check the quantity used. Use a minimum of 250mg/week (more if possible).

Anti-inflammatory Drugs
Corticosteroids and Calcineurin inhibitors are useful for shortand long-term use.

Topical Corticosteroids (TCS)

• Gold standard of treatment for AD
• Quick acting anti-inflammatory action. Potency from mild to very potent.
• General rule is that one uses the lowest potency possible for control of the disease. Goal is to be off the steroid more often than on the steroid.
• Useful for flare prevention.
• In conjunction with calcineurin inhibitors, they have a role
• as rescue medication when severe flares develop.
• Low potency corticosteroids are best used in the skin folds, face and neck.
• Moderate potency steroids are needed for thick lichenified eczema in older children and for acute flares on the body.
• Side-effects such as skin atrophy, tachyphlaxis, and adrenal suppression can occur but these are usually seen if the drug is used for too long, too often, or too much especially on the face folds, or inner thigh. Very young and old patients are more at risk. No harm will come from using potent corticosteriods for short periods, i.e., days at a time.
• Two issues of concern are steroid phobia by patients and
  steroid allergy:
  a) Steroid phobia — patients need to understand that the
  body naturally produces steroids and that side-effects are unlikely if topical steroids are used appropriately.
  b) Steroid allergy – Uncommon. Patch testing is required to confirm.

Topical Calcineurin Inhibitors
Pimecrolimus (Elidel™ 1% cream) Nonsteroid approved for short- and long-term intermittent use in mild-to-moderate AD over 2 years of age. Guidelines suggest use when other standard treatments fail or there is concern regarding risk of side-effects.

• Rapid relief (1-2 weeks) due to targeted anti-inflammatory action
• Used in practice to bring AD under control and also intermittently thereafter at first signs and symptoms of disease activity to prevent flare-ups. Topical corticosteroids can also be used but some physicians reserve them for more severe flares.
• Well-controlled studies in infants, children and adults demonstrate significant reduction in incidence of flares with the use of corticosteroids.
• Long-term studies show efficacy and safety in infants from 3-23 months, but it is not approved for this age range.
• Burning or stinging can be a problem but the likelihood is usually relative to disease severity. Patients do much better if warned of this transient effect.
• Long term safety – see Author’s Comment on recent FDA advisory.

Tacrolimus (Protopic™0.03% and 0.1%ointment) Non-steroid approved for short-term intermittent use in moderate- to-severe atopic AD over 2 years of age (0.03% >2yrs, 0.1% >15yrs). Guidelines suggest use when other standard treatments fail or concern regarding risk of side effects.

• Rapid relief (1-2 weeks) due to targeted anti-inflammatory action
• Used in practice to bring AD under control and also intermittently thereafter at first sign of disease activity or flare. TCS could be used as rescue medications for severe flares
• Long-term studies show safety and efficacy in > 2yr old.
• Burning or stinging can be a problem but the likelihood is usually relative to disease severity.
• Long term safety – see Author’s Comment on FDA advisory.

Infection Control

Clinical experience shows that AD may respond to anti Staph antibiotics even when there are no signs of a typical impetigo. Localized AD with probable secondary infection (swab if in doubt) use mupirocin cream, fucidic acid cream/ointment or oral cloxacillin or cephalosporin if widespread.

Authors’ Comments

Recently asked question: What is the role of calcineurin inhibitors in the control of eczema following the recent FDA Health Advisory?

It is the authors’ opinion that the recent Advisory about calcineurin inhibitors increasing the risk of cancer is based more on fear than fact. Granted that long-term use of oral immunosuppressive agents, such as in the transplant population, does raise the incidence of lymphoma, the degree of suppression is dose related. Rates of lymphoma and skin cancers in clinical trials and postmarketing surveillance reveal cancer rates that are much lower than would be expected in a control population. Evidence shows that both pimecrolimus and tacrolimus have very low systemic absorption when used topically as recommended for AD. Animal studies using oral formulations showed a higher rate of lymphoma, but at very high doses. What is clear is that people with AD have very significant disease that impacts most negatively on their quality of life. For the physician and patient there is no option other than to treat this disabling condition. With any medication there are always potential risks, but based on the available information the benefits of these medications far outweigh the risks. Resistant cases have been treated with UV light, azathioprine, cyclosporine, mycophenolate mofetil and systemic steroids.

It is significant that in a recent survey of leading dermatologists in North America and Europe conducted and published by Skin Therapy Letter© the majority of these doctors reported that they will not change their habit of prescribing topical calcineurin inhibitors, but are now likely to spend a little more time counseling and informing their patients who show concern.

^aPediatric and Adolescent Dermatology, Children’s Hospital and Health Center, San Diego, CA
^bUniversity of California School of Medicine, San Diego, CA

ABSTRACT

Pimecrolimus is an immunomodulating medication that inhibits production of inflammatory cytokines in the skin and this compound was specifically developed for the treatment of inflammatory skin diseases. Phase II and III clinical trials with the topical formulation of pimecrolimus (Elidel® cream, Novartis) have shown that it is safe and effective for use in patients with atopic dermatitis (AD). The US FDA recently approved Elidel® for use in patients ≥2 years of age with mild-to-moderate atopic dermatitis (AD).

Key Words:
pimecrolimus, immunosuppressant, atopic dermatitis

Pimecrolimus (formerly SDZ ASM 981) is a natural macrolide product derived from the fungus Streptomyces hygroscopicus var. ascomyceticus. The topical formulation of pimecrolimus (Elidel® cream, Novartis) is one of a new class of non-steroidal topical immunosuppressant medications. When applied topically, it has cutaneous anti-inflammatory activity and appears to be minimally absorbed into the circulation. Safety and efficacy of pimecrolimus 1% cream have been established in several wellcontrolled clinical trials involving children and adults with AD. This medication was approved by the US FDA for use in adults and children (≥2 years) with mild-to-moderate AD in December 2001, and is now widely available. The product is currently undergoing regulatory review in Europe and Canada.

Mechanism of Action

The mechanism of action is closely related to that of cyclosporine, an immunosuppressant medication useful in some inflammatory skin disorders refractory to standard therapy. Oral cyclosporine is quite effective but has significant toxicities. Unfortunately, it has been found in trials to be ineffective topically.¹ Efforts have been directed toward the development of new topical compounds with potent anti-inflammatory activity similar to cyclosporine, but without the systemic side effects. Topical tacrolimus and later, pimecrolimus, represent the first generation of this type of product. When applied topically, both medications selectively target inflammation in the skin without impairing systemic immune responses. In the early development phase of pimecrolimus, more than 400 ascomycin derivatives were synthesized and their characteristics explored in pre-clinical studies; SDZ ASM-981 was chosen for development because of its favorable safety profile and cutaneous efficacy.²

Pimecrolimus binds with high affinity to the T-cell receptor macrophilin 12, which leads to inhibition of calcineurin, a protein phosphatase required for activation of the T-cell. As a result, Tcell activation is inhibited, and transcription and release of proinflammatory cytokines is prevented. Additionally, pimecrolimus decreases mast cell production of pro-inflammatory cytokines (e.g., TNF-alpha) and IgE induced pro-inflammatory mediators (e.g., histamine).³ The ability of pimecrolimus to inhibit the activation of multiple cell lines and cytokines may account for its ability to effectively reduce inflammation.

In animal models, both topical and systemic pimecrolimus are highly effective against skin inflammation. However, in contrast to tacrolimus, oral pimecrolimus is a poor systemic immune suppressant,⁴ reducing the likelihood of systemic toxicity.

Drug Interactions

Potential interactions between pimecrolimus and other drugs have not been systematically evaluated. Systemic interactions are unlikely due to the low levels of pimecrolimus found in the blood after topical application, but cannot be ruled out based on data gathered to date. Studies with human liver microsomes indicate that pimecrolimus is metabolized in vitro by the CYP3A family of P450 enzymes. It appears to be eliminated almost completely in the bile. FDA labeling suggests that concomitant administration of known CYP3A inhibitors in patients with widespread disease be undertaken with caution.

Indications

To date, pimecrolimus has primarily been studied for use in AD, which is a chronic, highly pruritic inflammatory skin disorder and the most common chronic skin disease in childhood.⁵ The disease may be associated with significant morbidity and can have a significant impact on quality of life for patients and families. Additionally, research has shown that patients are often not satisfied with prescribed therapy.⁶

Until recently, topical treatment of AD has been limited to the use of corticosteroids. Patients who experienced side-effects from long-term use of the agents, or patients who were refractory to therapy had no other effective alternatives for topical treatment. Pimecrolimus and tacrolimus represent novel treatment options for this subset of patients.

Phase II and III trials of pimecrolimus have documented its safety and efficacy for AD treatment (summarized in Table 1). Although a few preliminary studies have been conducted using pimecrolimus to treat psoriasis and irritant hand dermatitis, its use has not yet been studied extensively for other skin conditions.^7-9 Oral pimecrolimus showed efficacy and tolerability when studied for moderate-to-severe plaque psoriasis. Topical pimecrolimus has also been studied for treatment of psoriasis and has demonstrated disease improvement when used under occlusion. A study of pimecrolimus for chronic irritant hand dermatitis found that the cream safely and effectively ameliorated the signs and symptoms of the disease after 6 weeks of therapy. Based on the studies to date, it is likely that pimecrolimus will be studied for a wide variety of inflammatory skin disorders in the future.

Table 1: Review of clinical trial data.

AD Clinical Trials

The efficacy and safety of pimecrolimus in patients with AD was shown in 1998, in a small, randomized, blinded, placebo controlled trial. In 34 adult patients, pimecrolimus 1% cream proved to be superior to placebo, and no clinically significant adverse events were reported.¹⁰

Another larger, phase III, multi-center, blinded, randomized dose-finding trial also suggested efficacy and safety of pimecrolimus. This study evaluated 260 patients who were randomized to receive either 0.05%, 0.2%, 0.6%, 1% pimecrolimus, vehicle or betamethasone valerate 0.1% cream twice daily for 3 weeks. The 0.2%, 0.6% and 1% pimecrolimus creams were found to be more effective than vehicle, with 1% being the most effective. Betamethasone valerate was more effective than all concentrations of pimecrolimus. Pimecrolimusrelated adverse events included burning and a feeling of warmth in the 0.6% and 1% groups (42.9% and 48.9%, respectively, vs. 34.9% with vehicle). Based on these findings, the 1% cream was chosen for further study in phase III trials.¹¹

Subsequently, 2 large, phase III, multi-center, randomized, controlled trials comparing pimecrolimus to vehicle were conducted in pediatric patients (aged 2-18 years) with AD. These two studies were of identical design, allowing for pooling of the results. Four hundred three patients were enrolled and both groups received treatment twice daily for 6 weeks. Efficacy was evaluated primarily by the Investigators Global Assessment (IGA), which uses a 6-point scale ranging from clear to very severe disease. The majority of patients studied had moderate disease. Treatment success was defined as achieving an IGA of 0-1 (clear to almost clear) during the study. At the first study visit (day 8), 12% of pimecrolimus patients achieved this, as compared to only 2.2% of vehicle patients (p<0.05). At the final study evaluation (day 43), 34.8% of pimecrolimus-treated patients were clear to almost clear, as opposed to only 18.4% of vehicle-treated patients (p<0.05). Pimecrolimus was also significantly more effective than vehicle at all visits for all secondary efficacy assessments studied (pruritus score and Eczema Area and Severity Index Score (EASI)). The incidence of adverse events was similar in both groups. The authors concluded that pimecrolimus 1% cream is safe and effective in children ≥2 years of age with mild-to-moderate AD.¹²

Another multi-center, randomized, controlled clinical trial was conducted, which compared pimecrolimus to vehicle in 186 children from 3-23 months of age. The design of this study was virtually identical to that of the two trials described previously. Patients applied medication twice daily for 6 weeks. The majority of the infants had moderate disease at study entry. By day 8, 17% of pimecrolimus-treated patients were clear or almost clear, compared with 9.5% in the placebo group (p = 0.174). By day 43 this increased to 54.5% of patients in the pimecrolimus group who were clear or almost clear and 23.8% of vehicle-treated patients (p<0.001). For all secondary efficacy parameters, pimecrolimus was significantly more effective than placebo. The incidence of adverse events was similar between the two groups. The authors concluded that pimecrolimus is safe and effective in infants aged 3-23 months with mild-to-moderate AD.¹³

Recently, a unique trial was conducted in pediatric patients aged 1-17 years, which suggested that pimecrolimus may be safe and effective maintenance therapy for preventing AD flares. The results also suggested a steroid-sparing effect in patients treated with pimecrolimus.¹⁴

Pharmacokinetics

Pharmacokinetic studies of pimecrolimus have been conducted with both adult and pediatric patients as young as 3 months of age. Measured blood concentrations of pimecrolimus were consistently low in both children and adults (99% had <2ng/ml) regardless of age, extent of body surface area (BSA) treated or duration of therapy. The majority of the readings were below the limit of quantification, even in the youngest patients. Over 12 months of treatment, there was no accumulation of the drug over time.¹⁵

Adverse Effects

Pimecrolimus cream is well tolerated when applied topically. Adverse effects have generally been limited to local irritation such as warmth, burning and pruritus. Unlike with topical corticosteroids, there has been no atrophy or adrenal axis suppression seen with Elidel®.

A significant concern exists related to local immunosuppression with topical application of tacrolimus and pimecrolimus. These agents inhibit T-cell activation and could therefore theoretically put patients at risk for conditions occurring more often in patients with T-cell suppression, namely skin cancer and viral infections. Incidence of these infections in completed trials was similar in the placebo and treated groups, but longer term data is needed to confirm that no association exists.

Conclusion

In summary, pimecrolimus cream is one of a new class of antiinflammatory medications that have a unique mechanism of action derived from inhibition of pro-inflammatory cytokines in the skin. It has been shown to be safe and effective in several randomized, controlled trials in patients with AD. Long term data is limited to 1 year of use and ongoing studies to assess long term safety are appropriate. Based on the information gathered to date, it is likely that in the future, pimecrolimus will be used extensively for AD and a variety of other inflammatory skin conditions.

References

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