Background: The effectiveness of Diphencyprone (DPC) in alopecia areata (AA) was demonstrated in several studies with highly variable response rates ranging from 5% to 85%.
Objective: The response rate and variable factors affecting the prognosis were studied focusing on long-term follow-up with or without maintenance therapy.
Methods: A total of 135 cases of AA were treated with DPC. Patients were divided into five groups according to the area of scalp affected: Grade 1 AA: 25-49% scalp affection; Grade 2 AA: 50-74% scalp affection; Grade 3 AA: 75-99% scalp affection; alopecia totalis and alopecia universalis. An initial response was defined as appearance of new terminal hair within treated sites. Excellent response was defined as terminal hair covering >75% of the scalp. Relapse meant >25% hair loss. Maintenance therapy meant ongoing therapy once every 1-4 weeks after excellent response. Follow-up was performed to detect any relapse of AA.
Results: Ninety-seven patients continued therapy for >or=3 months. After an initial 3 month lag, cumulative excellent response was seen in 15 patients (15.4%), 47 patients (48.5%), 51 patients (52.6%) and 55 patients (55.7%) after 6, 12, 18 and 24 months respectively in a mean median time of 12 months. The only patient variable affecting the prognosis was baseline extent of AA. Excellent response was seen in 100%, 77%, 54%, 50% and 41% in Grade 1, Grade 2, Grade 3, AA totalis and AA universalis patients respectively. Side-effects were few and tolerable. Hair fall >25% occurred in 17.9% of patients on maintenance and 57.1% of patients without maintenance therapy (P-value=0.025).
Conclusion: Diphencyprone is an effective and safe treatment of extensive AA. A long period of therapy is needed and will increase the percentage of responders especially in alopecia totalis and universalis. Maintenance therapy is recommended to reduce the risk of relapse.