INTRODUCTION
Atopic dermatitis (AD) affects 1-3% of the adult population
and is associated with asthma and allergic rhinitis.
1 While onset and resolution typically occur in childhood, the condition may persist into adulthood or even be newly diagnosed in adults. Both hereditary and environmental factors contribute to the development of AD but a precise understanding
of the complex interplay between genes and the environment is unknown.
Allergic contact dermatitis (ACD) is an acquired inflammatory condition in response to an environmental allergen that usually presents in adulthood.2 ACD has a high prevalence in North America
and Western Europe, where over 20% of people in the general population have a contact allergy to at least one allergen.1 In patch testing results, the most common allergens include nickel, neomycin
sulfate, and fragrance.3
Patients with moderate to severe AD and ACD often require systemic treatments such as cyclosporine, systemic steroids, methotrexate, azathioprine, and mycophenolate mofetil. These treatments have multiple adverse side effects.
Apremilast is an oral agent that modulates multiple anti-inflammatory
pathways through PDE4 inhibition. PDE4 inhibitors increase intracellular cyclic adenosine monophosphate (cAMP), which activates protein kinase A and other downstream effectors
resulting in the inhibition of pro-inflammatory cytokines. In human cellular models, apremilast has been shown to decrease tumor necrosis factor alpha (TNF-α), interferon gamma (IFN-γ), interleukin (IL)-2, IL-8, IL-12, IL-23, and leukotriene B4 (LTB4).4 In a phase 2 clinical trial, apremilast, 20 mg once daily, demonstrated
efficacy in subjects with severe psoriasis where epidermal thickness was reduced by a mean of 20.5% and fourteen out of nineteen subjects demonstrated improvement in PASI scores after
29 days of treatment.5 In this study, apremilast treatment was associated with a significant decrease in inducible nitric oxide synthase (iNOS) mRNA expression within the psoriatic lesions.5 In a recent press release, it was reported that 41% of subjects achieved PASI-75 with 30 mg BID apremilast compared to 6% on placebo (P<0.001) after 16 weeks of treatment.6
A topical PDE4 inhibitor has previously been studied for the treatment of atopic dermatitis, with positive results. CP-80633