The consequences of atopic dermatitis reach beyond the skin and past childhood. Patients with atopic dermatitis are at risk of developing allergic comorbidities, but less is known about the associations between atopic dermatitis and non-allergic conditions. Understanding these non-allergic comorbidities has the potential to improve patient outcomes and to help mitigate the cost and burdens associated with these conditions. Atopic dermatitis is associated with cutaneous bacterial infections, more severe forms/courses of cutaneous viral infections, and extra-cutaneous infections. Atopic dermatitis is also associated with several mental health comorbidities particularly attention-deficit hyperactivity disorder, anxiety, and depression. Data are largely inconsistent for specific cancers, but atopic dermatitis appears to protect against malignancy overall; severe long-term atopic dermatitis is associated with adult lymphomas. Atopic dermatitis may also be associated with obesity, cardiovascular disease, and autoimmune disease, particularly alopecia areata and gastrointestinal immune-mediated disorders. Although the causative mechanisms underlying these associations are poorly understood, treating physicians should be aware of associations in seeking to alleviate the burden for patients with atopic dermatitis.

Topical calcineurin inhibitors (TCIs), commercially available since 2000–2001, are the first and only topical medications approved for chronic treatment of atopic dermatitis (AD) in pediatric patients and remain a welcomed alternative to topical corticosteroids. In January 2006, the US Food and Drug Administration (FDA) issued a boxed warning requirement based on a theoretical risk of malignancy (including lymphoma) with TCI use. However, in the years since, analyses of epidemiologic and clinical data have failed to demonstrate a causal relationship between TCI use and malignancy or lymphoma risk, especially for pimecrolimus cream. In fact, the observed number of malignancies and lymphomas observed both in post-marketing surveillance and reported to the FDA using its adverse events reporting system is much lower among TCI-exposed patients than the expected number for the general population. Furthermore, among children enrolled in post-marketing pediatric registry studies for both tacrolimus and pimecrolimus followed for up to 5.5 years [10,724 patient-years (PY)] or 6.5 years (16,219 PY), respectively, the observed number of malignancies and lymphomas is very low and similar to the number expected for a sample of similar size in the general population. In addition to reporting these comparative malignancy and lymphoma data, this article provides a historical overview of the boxed warning requirement and critically evaluates the preclinical, clinical, and epidemiological evidence that has thus far failed to substantiate a relationship between TCI use and malignancy. The authors also provide practical clinical advice for optimizing AD management and patient care in the context of the boxed warning.

BackgroundMany clinicians have concerns about the safety of atopic dermatitis (AD) treatments, particularly in children requiring long-term daily maintenance therapy. Topical corticosteroids (TCS) have been widely used for >5 decades. Long-term TCS monotherapy has been associated with adverse cutaneous effects including atrophy, rebound flares, and increased percutaneous absorption with potential for adverse systemic effects. Topical calcineurin inhibitors (TCIs), tacrolimus and pimecrolimus, available for 1–2 decades, are not associated with atrophy or increased percutaneous absorption after prolonged use and have much lower potential for systemic effects. However, since 2006 TCIs have carried a controversial Boxed Warning based on a theoretical risk of malignancy (eg, skin and lymphoma) that has limited TCI use for standard-of-care maintenance therapy.MethodsA comparative systematic search of PubMed was done for long-term (≥12 week) clinical trials of TCS or TCI treatment in patients <12 years with AD. Citations were reviewed for inclusion based on MeSH terms, abstracts, and relevant article text. Studies were excluded if they did not encompass subjects <12 years, or were <12 weeks’ duration, retrospective, meta-analyses, or limited to anecdotal case reports.ResultsOf 27 trials meeting criteria, 21 included 5825 pediatric patients treated with TCIs, and 6 included 1999 patients treated with TCS. TCS studies were limited to low- to mid-potency products, and all but one study lacked a vehicle control. Eight TCI studies were vehicle-controlled, and safety data were well reported, with ≤5 % of patients reporting discontinuation due to adverse effects (DAEs). Cutaneous and systemic adverse events (AEs) were similar in TCI and vehicle groups, with no reports of lymphoma. Safety data in TCS trials were less well reported. DAE incidence was addressed in just 2 trials, and systemic and cutaneous AEs were mostly unreported.ConclusionsData supporting long-term use of TCIs are robust, documenting safety and efficacy, while data supporting long-term TCS use are limited to low- to mid-potency products. Our review identifies a lack of information on the safety of commonly prescribed, long-term monotherapy with mid- to high-potency TCS in pediatric AD, and supports standard-of-care maintenance therapy with TCIs and intermittent use of low- to mid-potency TCS for flares.

Atopic dermatitis is the most common chronic skin disease, and it primarily affects children. Although atopic dermatitis (AD) has the highest effect on burden of skin disease, no high-level studies have defined optimal therapy for severe disease. Corticosteroids have been used to treat AD since the 1950s and remain the only systemic medication with Food and Drug Administration approval for this indication in children, despite published guidelines of care that recommend against this option. Several clinical trials with level 1 evidence have supported the use of topical treatments for mild to moderate atopic dermatitis in adults and children, but these trials have had little consistency in protocol design. Consensus recommendations will help standardize clinical development and trial design for children. The Food and Drug Administration issues guidance documents for industry as a source for "the Agency's current thinking on a particular subject." Although they are nonbinding, industry considers these documents to be the standard for clinical development and trial design. Our consensus group is the first to specifically address clinical trial design in this population. We developed a draft guidance document for industry, Developing Drugs for Treatment of Atopic Dermatitis in Children (≥3 months to <18 years of age). This draft guidance has been submitted to the Food and Drug Administration based on a provision in the Federal Register (Good Guidance Practices).

IntroductionTreatment guidelines endorse a variety of strategies for atopic dermatitis (AD) which may vary from published data and clinical practice patterns. The objective of this review was to quantify the volume of available medical literature supporting pediatric AD treatments and compare these patterns to those recommended by published guidelines and/or clinical practice patterns.MethodsSearches of Embase (2005–2016) and abstracts from selected meetings (2014–2016) related to AD treatment in patients younger than 17 years of age yielded references that were assessed by study design, primary treatment, age groups, and AD severity.ResultsPublished literature partially supports clinical guidelines, with emollients and topical medications being the most investigated. There were disproportionately more publications for topical calcineurin inhibitors (TCI) compared with topical corticosteroids (TCS); however, the search interval may have biased the results toward treatments approved near the beginning of the time frame. In contrast, publications documenting clinical practice patterns reflect greater use of emollients and TCS (over TCI), as well as systemic corticosteroids. Data is relatively limited for long-term and combination treatment, treatment of severe AD, and patients younger than 2 years of age, and completely lacking for systemic corticosteroids.ConclusionThis scoping review demonstrates that available medical literature largely supports published guidelines for topical therapy; however, clinical practice patterns are less aligned. There is a lack of data for older, more frequently used generic treatments, including oral antihistamines, oral antibiotics, and systemic corticosteroids. Overall, literature is lacking for long-term treatment, treatment for patients younger than 2 years of age, and for systemic treatment for severe disease.FundingRegeneron Pharmaceuticals Inc.