Prognostic factors for cure following treatment of onychomycosis

[[[ Objective: ]]] To examine if host baseline factors and week 24 mycology results are associated with mycological and clinical cure in patients with onychomycosis treated with oral terbinafine. [[[ Design: ]]] Open pilot study to determine prognostic factors in the treatment of onychomycosis. [[[ Setting: ]]] Outpatient dermatology clinic. [[[ Patients: ]]] A total of 199 patients from the Icelandic arm of a trial comparing continuous terbinafine with intermittent terbinafine in onychomycosis were recruited for additional observation. [[[ Main outcome measures: ]]] Mycological, clinical and complete cure of the target toenail 72 weeks after treatment was initiated. [[[ Results: ]]] Patients with matrix involvement or slow nail growth were less likely to reach mycological, clinical and complete cure. Lateral involvement affected complete and mycological cure rates negatively. Patients with a dermatophytoma were less likely to reach mycological cure. Patients with a history of prior infection, men and older patients were less likely to reach clinical cure. Positive culture at 24 weeks affected mycological and clinical cure at 72 weeks negatively. [[[ Limitations: ]]] Only patients treated with terbinafine were considered. [[[ Conclusions: ]]] Several host-related factors at baseline and positive culture at 24 weeks had negative effects on cure of onychomycosis 72 weeks after treatment was initiated. This finding merits a large study on prognostic outcome factors in onychomycosis.