Topical immunotherapy with diphenylcyclopropenone in the treatment of chronic extensive alopecia areata.

Highly variable results have been described for the use of topical diphenylcyclopropenone (DPCP) in the treatment of alopecia areata (AA). We enrolled 41 patients in a prospective open clinical trial. Of these, 17 patients had either AA totalis (AAT) or AA universalis (AAU), and 24 had severe alopecia (> 50% scalp involvement). After sensitization with DPCP 2% in acetone, progressively higher concentrations were applied once a week for a period of 6-12 months. Of the 41 patients, 38 (16 with AAT or AAU and 22 with extensive AA) completed therapy. Significant hair regrowth was observed in 15 of the 38 patients (39.5%) at 6 months: 5 with AAT or AAU (31.25%) and 10 with extensive alopecia (45.4%). The above results were sustained in 66.6% of patients for a 12-month-follow up- period. In our study, topical immunotherapy with DPCP proved to be an effective treatment, with prolonged therapeutic results.