Prognostic factors for cure and recurrence of onychomycosis

Abstract

Background: The cure of onychomycosis (OM) requires long-term oral antifungal treatment, and recurrences after successful treatment are relatively common (10-53%). Objective: We sought to determine the factors affecting the duration of treatment and identify risk factors for recurrence. Methods: We retrospectively reviewed successfully treated consecutive cases of onychomycosis between January 2006 and February 2010. We classified the patients into 7 groups: distal subungual onychomycosis (DSO) type I (∼25% involved), type II (25-50%), type III (50-75%), type IV (75-100%), proximal subungual onychomycosis (PSO), superficial white onychomycosis (SWO), and candidal OM. The patients were treated with systemic agents including terbinafine, fluconazole and itraconazole. We analyzed the clinical data for factors affecting the duration of treatement and recurrence of onychomycosis. The factors included age, sex, subtype of onychomycosis, type of systemic antifungal agent as well as the existence of comorbidities. Results: A total of 227 patients were enrolled: their mean age was 56.9 years (range, 11-90); mean duration of treatment was 7.2 months (range, 1-24). The duration of treatment of DSO type I (6.2 months) was shorter than that of DSO III (8.5 months) and IV (9.0 months). The other factors including age, sex, the existence of diabetes or vascular disease, and the type of systemic agents did not affect the duration of treatment. The recurrence rates after successful treatment were 12.5% in the patients with diabetes and 2.6% in the patients without diabetes (p = 0.026). There was no difference in recurrence rates of the patients with or without vascular diseases. Conclusion: The duration of treatment to cure OM increased with the degree of involvement of DSO. No other factors affected the treatment duration significantly, recurrence rate was significantly higher in patients with diabetes.