Daylight photodynamic therapy with methylene blue in plane warts: a randomized double-blind placebo-controlled study

Conventional photodynamic therapy is associated with inconveniently long clinic visits and discomfort during therapy. Daylight-photodynamic therapy (DL-PDT) is an effective treatment, nearly pain free and more convenient for both the clinics and patients. There are no published studies of methylene blue (MB) as a photosensitizer (PS) used in DL-PDT.

Forty patients had multiple plane warts; 20 patients were subjected to DL-PDT with topical 10% methylene blue gel, and 20 patients were subjected to DL-PDT with hematoxylin (placebo). Improvement was evaluated by change of the number of warts and the dermoscope picture.

A total of 20 (100%) patients in group II showed no response to placebo, 13 patients (65%) in group I showed complete clearance, 2 (10%) patients showed a good response, and 5 (25%) patients had poor response to treatment (P < 0.01). No serious side effects and patients tolerated the pain well. No relapse was detected during the follow-up period (12 months).

Daylight exposure was not monitored with a dosimeter.

Daylight-PDT using MB is safe, easy to carry out, economic, effective, acceptable cosmetic results with no recurrence, convenient especially for children and nearly painless treatment.