Abstract: The common therapies of alopecia areata (AA) include topical medications (corticosteroid, minoxidil, etc.), systemic medications (oral corticosteroid, methotrexate, cyclosporine, etc.) and physiotherapy (e.g. photochemical therapy PUVA, 308-nm excimer laser, etc.). Phosphodiesterase-4 (PDE-4) inhibitors regulate a range of cytokines by increasing intracellular cyclic adenosine monophosphate (cAMP) levels. Previous animal model studies and a series of case reports have shown that oral PDE-4 inhibitors can treat baldness, but there are more adverse side effects. Crisaborole ointment is a kind of phosphodiesterase-4 (PDE-4) inhibitors, which have been reported in the treatment of atopic dermatitis, psoriasis and vitiligo. Phase 2 clinical trial of criborol ointment in the treatment of alopecia areata is under way, and there is no report about criborol ointment on the treatment of alopecia areata at home and abroad. We recently admitted to a patient who was treated with PDE-4 inhibitors for alopecia areata successfully, with no obvious adverse reaction.

Key words: Phosphodiesterase-4 inhibitor, PDE-4 inhibitor, criborol ointment, alopecia areata