In a Danish multi-practice study the efficacy of erythromycin tablets (Abboticin 500 mg tablets), fusidic acid cream (Fucidin cream), and placebo was compared in 86 patients (71 men and 15 women) with erythrasma. The patients were treated 'double-blind' for 14 days with either active tablets + placebo cream, placebo tablets + active cream, or placebo tablets + placebo cream. The signs of erythrasma, i.e. colour intensity, demarcation, and scaling of the affected area, as well as degree of fluorescence under Wood's light, were recorded before treatment, after one and two weeks, and at follow-up four weeks later. Cure/improvement was obtained in 77% of the cases in the erythromycin group, 87% in the fusidic acid group, and 42% in the placebo group. There was no difference between the active preparations, whereas both were significantly better than placebo, P = 0.01.