Jonathan I. Silverberg, Diane B. Nelson, Gil Yosipovitch

Atopic dermatitis (AD), a chronic inflammatory skin disease affecting children and adults, presents as mild-to-moderate disease in the majority of patients. Pruritus, one of the key diagnostic criteria for AD, is associated with reduced quality of life and disease aggravation. Current treatments include emollients and topical pharmaceutical agents. Topical corticosteroids (TCSs) are commonly used, but are associated with safety concerns with cutaneous and systemic side effects. Topical calcineurin inhibitors (TCIs) inhibit T-lymphocyte activation, but their use is limited because of application-site infections and a boxed warning for potential malignancy risk. Despite recent reports indicating there is no malignancy risk, long-term treatment with TCIs is still considered with hesitancy. In addition, while both TCSs and TCIs provide some relief of pruritus, it often takes over a week for improvement to occur. The development of a more specific anti-inflammatory treatment which is easy to use and targets pruritus could provide clinically meaningful improvements for patients with AD. The majority of emerging therapies for AD are focused on inhibiting phosphodiesterase 4 (PDE4), an enzyme which is increased in inflammatory disorders such as AD. This review will update readers on the recent advances in topical therapies, including PDE4 inhibitors, for the treatment of AD.