Onychomycosis--treatment, relapse and re-infection.

The treatment of onychomycosis has improved considerably following the introduction of the oral antifungals terbinafine and itraconazole. The pharmacokinetic characteristics of both these drugs has made short treatment times effective. Patients with a culture-proven dermatophyte infection of the toe-nails, receiving terbinafine 250 mg daily for 12 weeks, have a 70% chance of cure. The risk of relapse is probably less than 10%, and this may be prevented by a further course of terbinafine should the expected increasing length of unaffected nail growth stall or cultures become positive. Once cured, the regular and prophylactic use of an effective topical antifungal may help to prevent a recurrence of tinea pedis and onychomycosis.