Efficacy and safety of diphenylcyclopropenone alone or in combination with anthralin in the treatment of chronic extensive alopecia areata: a retrospective case series.

Background: Some patients with chronic extensive alopecia areata (AA) may be refractory to topical immunotherapy. Combination therapy is recommended for such patients. Efficacy and safety of a combination therapy with diphenylcyclopropenone (DPCP) and anthralin in chronic extensive AA is unknown.

Objective: We sought to determine whether the combination therapy of DPCP and anthralin is superior to DPCP alone in chronic extensive AA.

Methods: We retrospectively analyzed the efficacy, side effects, and relapse rates of DPCP (alone or with anthralin) in chronic extensive AA.

Results: A total of 47 patients (22 were treated only with DPCP, and 25 with DPCP and anthralin for at least 30 weeks) were evaluated. Complete hair regrowth was observed in 36.4% and 72% of the patients who received DPCP and combination therapy, respectively (P = .01). Hair regrowth duration was shorter with combination therapy (P = .01). Regrowth rates of the eyebrows, eyelashes, and beard in patients on combination therapy were higher than those in patients on DPCP (P = .01). Side effects such as folliculitis, hyperpigmentation, and staining of skin, hair, and clothes were more common in combination therapy group.

Limitations: The retrospective design and small number of patients are limitations.

Conclusion: Combination therapy with DPCP and anthralin is superior to DPCP alone in chronic extensive AA.