Difamilast for the treatment of atopic dermatitis

Atopic dermatitis (AD) is a common chronic relapsing inflammatory skin disease. The pathogenesis of AD is complex and still not fully understood. Despite recent therapeutic developments, the current therapeutic arsenal of AD remains limited and is associated with long-term efficacy and safety issues. Therefore, new topical therapies with different mechanisms of action are required to overcome the limitations of existing treatments. Difamilast is a phosphodiesterase 4 inhibitor currently in phase 3 studies. Difamilast shows antipruritic and anti-inflammatory properties and a rapid onset of action, with significant differences in some parameters from the vehicle within 1 week of treatment. Phase 2 and 3 clinical trials have shown that difamilast ointments are effective and well tolerated in adult and pediatric patients with AD, and are expected to be used for long-term AD treatment. In 2021, difamilast was the first phosphodiesterase 4inhibitor to acquire manufacturing and marketing approval in Japan for the treatment of adult and pediatric patients (2 years of age and older) with AD. This article is a narrative review of the current literature on difamilast in the management of AD.