Comparison of Diagnostic Methods for Onychomycosis: a Controlled, Prospective Study

Objective: Standard KOH preparation and fungal culture are the most preferred methods used for the diagnosis of onychomycosis. Alternatively used methods are histopathological examination and KOH preparation for 24 hours. Our aim was to assess the sensitivity of standard KOH preparation, KOH preparation for 24 hours, fungal culture and histopathological examination for the diagnosis of onychomycosis. Material and Methods: Nail samples were taken from 58 patients with a clinical suspicion of onychomycosis. Standard KOH preparation, KOH preparation for 24 hours, fungal culture and histopathological examination were searched for presence of fungal elements. Results: Onychomycosis was diagnosed in 46 samples. Samples of 8 patients were negative by all methods. Fungal elements were observed by standard KOH preparation in 27 patients (50%), by KOH preparation for 24 hours in 37 patients (68.5%), by culture method in 14 patients (25.9%) and by histopathological examination in 40 (74.1%) patients. The sensitivity values of these methods were 58%, 80.4%, 30.4%, and 87% respectively. Conclusion: This study showed that histopathological examination and KOH preparation for 24 hours methods are more sensitive than the KOH preparation and fungal culture. (Turk J Dermatol 2011; 5: 48-52)