Successful treatment and prophylaxis of scalp seborrhoeic dermatitis and dandruff with 2% ketoconazole shampoo: results of a multicentre, double-blind, placebo-controlled trial

Pityrosporum ovale appears to play an important role in the pathogenesis of seborrhoeic dermatitis. Ketoconazole is an antimycotic agent with a high in vitro and in vivo efficacy against P. ovale. We performed a multicentre study to investigate the efficacy of ketoconazole 2% shampoo in the treatment and prophylaxis of seborrhoeic dermatitis and dandruff. Five hundred and seventy‐five patients presenting with moderate to severe seborrhoeic dermatitis and dandruff of the scalp were treated with 2% ketoconazole shampoo twice weekly for 2–4 weeks, producing an excellent response in 88%. Of those patients who responded, 312 were included in a prophylactic phase, lasting 6 months. These patients were treated with the active preparation (shampoo containing 2% ketoconazole) once‐weekly, once every other week, alternating with placebo (shampoo without ketoconazole), or with placebo only once‐weekly. Forty‐eight (47%) patients in the placebo group experienced a relapse of seborrhoeic dermatitis, compared with 23 (19%) patients in the active treatment group, and 31 (31%) patients in the active/placebo group. The medication was well tolerated in all three groups. We conclude that ketoconazole 2% shampoo is highly effective, not only in clearing scalp seborrhoeic dermatitis and dandruff, but also in preventing relapse of the disease when used prophylactically once weekly.