Onychomycosis is caused most commonly by Trichophyton rubrum or T. mentagrophytes. About 10% of all persons worldwide and 40% of those ≥60 years old are believed to have the disease. Risk factors include older age, diabetes, poor peripheral circulation, smoking, HIV infection, psoriasis, and immunosuppression. Left untreated, onychomycosis can cause nail plate destruction, ingrown nails, and (particularly in patients with diabetes) secondary infections. Guidelines on treatment of onychomycosis have been published.

The FDA has approved a 0.3% foam formulation of the phosphodiesterase-4 (PDE4) inhibitor roflumilast (Zoryve – Arcutis) for topical treatment of seborrheic dermatitis in patients ≥9 years old. Roflumilast is the first PDE4 inhibitor to be approved in the US for this indication. It is also available in a 0.3% cream formulation (Zoryve) for treatment of plaque psoriasis and in an oral formulation (Daliresp, and generics) for treatment of chronic obstructive pulmonary disease. A 0.15% cream formulation for treatment of atopic dermatitis in patients ≥6 years old will be reviewed...