Successful treatment of resistant alopecia areata with a phototoxic dose of ultraviolet A after topical 8-methoxypsoralen application

Background: The efficacy of a phototoxic dose of ultraviolet A (UVA) after topical application of 8‐methoxypsoralen (8‐MOP) in the treatment of alopecia areata (AA) was evaluated previously in only one study. However, the possibility of spontaneous regrowth of hair cannot be excluded as sessions were carried out every 3 months. Objective: To determine the efficacy of a phototoxic dose of UVA after topical application of 8‐MOP in the treatment of AA resistant to other lines of treatment. Subjects/Methods: Thirty‐five patients with AA were treated by topical 8‐MOP application to the lesions followed by UVA irradiation using a phototoxic dose every 3 months for a maximum of four sessions. Severity grading of AA was carried out using the Severity of Alopecia Tool (SALT) score before and after treatment. Results: Fifty‐seven percent of patients showed a positive treatment response (40% showed complete and 17% showed partial response) with significant improvement of SALT score. The mean cumulative UVA dose was 22±8.3 J/cm². Mild reversible side effects were observed in 63% of patients after the first session. Conclusion: Phototoxic psoralen and ultraviolet A therapy after topical application of 0.1% 8‐MOP is an effective treatment option for resistant AA, with low total cumulative UVA dose, few treatment sessions, and minimal reversible side effects.