Investigations of the efficacy of diphenylcyclopropenone immunotherapy for the treatment of warts.

BACKGROUND: Diphenylcyclopropenone (DPCP) immunotherapy has been used to treat warts, particularly in patients, such as children, who cannot endure treatment-related pain and in patients with large numbers of warts. However, the efficacy of DPCP immunotherapy remains subject to much controversy. Specifically, cure rates and treatment durations have varied across reports, primarily because of the lack of large-scale studies.

METHODS: We performed an uncontrolled, open-label study to investigate the efficacy of DPCP immunotherapy for the treatment of cutaneous warts. A total of 170 patients with warts were enrolled in this uncontrolled, open-label study from 2006 to 2012. Each patient was sensitized with 0.1% DPCP. Two weeks after sensitization, DPCP was applied to warts once per week.

RESULTS: We achieved high clearance rates in 141 of 170 patients (82.9%) and 434 of 511 lesions (84.9%). Immunotherapy with DPCP was much more effective when the lesions were located on the hands and when the patient was aged < 20 years. The mean ± standard deviation number of applications was 9.02 ± 2.59. At the end of treatment, the most common final concentration was 0.1%, and most (77.0%) patients used a final concentration of > 0.005%. Side effects occurred in 36 patients, but no serious adverse effects occurred, and blistering at the sensitized site was the most common adverse effect.

CONCLUSIONS: Immunotherapy with DPCP is an effective and well-tolerated option for the treatment of recalcitrant warts.