Prevalence of Onychomycosis among Patients with Transverse Overcurvature of the Nail: Results of a Cross-Sectional Study

Introduction: Transverse overcurvature of the nail (TON) represents one of the main reasons for dermatological consultations due to nail conditions. Association between TON and subungual hyperkeratosis is common and simulates onychomycosis, constituting a difficult differential diagnosis by clinical features. Many cases are treated in daily practice with antifungal therapy even without mycological confirmation. The aim of this study was to determine the prevalence of onychomycosis among patients with TON associated with subungual hyperkeratosis. Methods: All subjects with clinical diagnosis of TON and subungual hyperkeratosis were subjected to a thorough clinical history, detailed clinical examination, digital photography, and collection of nail clipping and subungual debris for histopathological and microbiological examination (direct microscopy). Results: Sixty-five samples were collected from 62 female (95.4%) and 3 male (4.6%) participants. Age range was between 34 and 83 years (mean age, 61.2 years). Twenty-eight samples were positive for onychomycosis, giving a 43.07% prevalence rate of onychomycosis among TON associated with hyperkeratosis. Discussion/Conclusion: According to our data, the prevalence of onychomycosis in patients with TON associated with subungual hyperkeratosis was 43.07%, confirming the need to rule out fungal infection in TON associated with subungual hyperkeratosis prior to considering any unnecessary antifungal treatment.