Oral metronidazole treatment of lichen planus.

BACKGROUND

Oral metronidazole has been reported to be effective in some patients with idiopathic lichen planus (LP) who did not have concomitant protozoal infections of the intestinal or genital tracts.

OBJECTIVE

Our purpose was to evaluate the efficacy of this drug in the treatment of generalized LP.

METHODS

Nineteen patients with LP who were free from intestinal and genital protozoal infections were treated with oral metronidazole, 500 mg twice daily, for 20 to 60 days and were followed up for a period of 5 to 36 months.

RESULTS

Fifteen patients (78.9%) improved with metronidazole treatment. Complete response was observed in 13 patients (7 women and 6 men). Two patients responded partially. Worsening of the lesions was observed in 1 of the 4 nonresponding patients.

CONCLUSION

Metronidazole may be an alternative therapy for the treatment of generalized LP. Its immunomodulatory activity seems to be a possible mechanism of action besides its antimicrobial activity.