Topical immunotherapy with diphenylcyclopropenone of patients with alopecia areata--a large retrospective study on 142 patients with a self-controlled design

Background: Although diphenylcyclopropenone (DCP) is frequently used for the treatment of alopecia areata (AA), large studies with more than 100 patients are still scarce.

Objective: To determine the efficacy of DCP immunotherapy in a large cohort of patients with AA who had been treated in our institute from January 2000 to December 2006.

Methods: A total of 142 patients with AA undergoing topical DCP therapy in a self-controlled design were evaluated retrospectively.

Results: Seven patients (4.9%) were anergic to DCP. Two of 135 patients (1.5%) discontinued DCP therapy because of adverse effects. Fifty-one patients (37.8%) had a complete response (CR: >90% re-growth of hair), 20 patients (14.8%) exhibited a partial response (PR: >50-90% re-growth), 26 patients (19.3%) experienced a minimal response (MR: 10-50% re-growth) and 38 patients (28.1%) had no response after DCP therapy (NR: <10% re-growth). Bivariate logistic analysis revealed that severity of hair loss at the beginning of DCP (P=0.001) is the only significant prognostic factor for therapeutic outcome. Twenty-three patients (45.1%) with CR had relapses upon discontinuation of the treatment or even during prolonged DCP therapy.

Conclusion: Topical immunotherapy with DCP of patients with AA is rather effective and mostly well tolerated. The extent of hair loss before therapy is the main predictor for the therapeutic success of DCP. However, DCP therapy is associated with a high degree of relapse of which patients should be well informed.