Double-Blind Trial of 1% Clotrimazole Cream and Whitfield Ointment in the Treatment of Pityriasis Versicolor

To the Editor.— We have recently completed a double-blind trial of clotrimazole (Lotrimin, [Canesten (Br)]) compared with benzoic and salicylic acid (Whitfield) ointment in the treatment of pityriasis versicolor. Clotrimazole is a tritylimidazole derivative with a wide spectrum of antifungal activity including in vitro fungistatic activity against Malassezia furfur.1One percent clotrimazole cream is as effective as Whitfield ointment and more acceptable to the patient. Culture of Malassezia furfur showed a constant and persistent sensitivity to clotrimazole, suggesting its suitability for treatment of relapse. Clinical assessment of hypopigmented lesions at follow-up is not as reliable a test of cure as microscopy of scrapings. Method.— During a two-year period, all patients seen in the skin department and found to be positive for Malassezia furfur on microscopy of skin scrapings were included in the trial. The patients were allotted at random to treatment with Whitfield ointment (3% salicylic acid and