Tinea versicolor: treatment and prophylaxis with monthly administration of ketoconazole.

Twenty-two patients with tinea versicolor (pityriasis versicolor) were treated with a single 400 mg dose of ketoconazole and evaluated one month later. All patients were found to be clinically cured when examined with Wood's light and microscopic techniques approximately one month after the initial dose. Hypopigmented macules persisted for several months in most patients. Prophylaxis with single monthly doses of 400 mg of ketoconazole has resulted in one recurrence to date, with follow-up for four to fifteen months (mean of 8.2 months) in twenty patients. No side effects from ketoconazole were reported by any of the patients.