Is topical metronidazole effective in seborrheic dermatitis?: A double-blind study

Background Seborrheic dermatitis is a common, chronic, papulosquamous dermatosis. Although several types of treatment have been developed, repetitive treatment courses are often necessary. Aim To perform a randomized, placebo-controlled, double-blind clinical study with metronidazole 0.75% gel in patients with mild to moderate seborrheic dermatitis of the face. Methods Eighty-four patients (52 males and 32 females) with seborrheic dermatitis were enrolled in the study. Patients were randomly allocated to the application of metronidazole 0.75% gel or placebo to their facial lesions, twice daily for 8 weeks. Patients were scored with regard to the severity of the lesions at the initial evaluation and every 2 weeks for 2 months. All patients were evaluated for a final assessment of improvement at the end of the study. Results At baseline, both treatment groups were comparable in terms of demographic data and lesion severity score. Seventy-eight patients (48 males and 30 females), 48 (62%) in the metronidazole group and 30 (38%) in the placebo group, completed the study. Two patients in the metronidazole group and four patients in the placebo group left the study. There was no statistically significant difference in the change in the mean severity score between the two groups at the end of the study (P > 0.05). At the final evaluation of the response at 8 weeks, no statistically significant difference was found between the treatment groups (P > 0.05). Metronidazole gel was generally tolerated well during the study. Conclusions Metronidazole 0.75% gel and placebo show similar efficacy in the treatment of seborrheic dermatitis.