Clinical Efficacy of Diphenylcyclopropenone in Alopecia Areata: Retrospective Data Analysis of 50 Patients

This retrospective study analyzed the efficacy of diphenylcyclopropenone (DPCP) in treating 50 patients with extensive alopecia areata (AA) at the Cleveland Clinic Foundation. The study found that DPCP was effective, with 71% of alopecia totalis (AT) and 56% of alopecia universalis (AU) patients achieving 50% or more terminal hair regrowth. Common side effects included itching, dermatitis, mild blistering, and local lymphadenopathy, which were manageable. The study suggested that DPCP therapy should continue for at least 2 years to identify responders, as 95% of responders showed regrowth within this period. Poor response predictors included extensive scalp hair loss, body hair loss, and a history of thyroid disease, which also predicted relapse. Further prospective double-blind randomized studies were recommended to validate these findings.