P7.80 The optimal dose of topical diphenylcyclopropenone sensitization for the treatment of alopecia areata: preliminary study

Myung Im, Young Joon Seo, Jeung Hoon Lee, Jang Kyu Park.

Department of Dermatology, College of Medicine, Chungnam National University, Teajon, Korea

Background: Topical immunotherapy with diphenylcyclopropenone(DPCP) for the treatment of severe alopecia areata is quite effective and well tolerated therapy. This treatment requires induction of a contact allergy to DPCP before its topical application. OBJECTIVE: In general, 1.5 or 2.0% DPCP is used for inducing sensitization. However, this concentration is not optimized and occasionally gives rise to patient discomfort due to its unpredictable side effects. Therefore, evaluation of the minimal concentration needed for DPCP sensitization is warranted.

Methods: Total thirty-three healthy people were enrolled in an open label clinical trial. They were sensitized with 0.1%, 0.5%, 1.0%, 1.5% DPCP 0.1ml on 2cm² area on each four extremities. Thirty-two of 33 people completed this study.

Results: Sensitization was occurred to 15.6 %(5 of 32) in 0.1% DPCP, 40.6%(13 of 32) in 0.5% DPCP, 84.4%(27 of 32) in 1.0% DPCP, 93.8%(30 of 32) in 1.5% DPCP. Conclusions: We consider 1.0% DPCP to be the most suitable minimal concentration for inducing sensitization in topical immunotherapy. We plan to apply this conclusion to alopecia areata patients for topical DPCP sensitization, and evaluate its therapeutic effect.