Subungual hyperkeratosis nail biopsy: a better diagnostic tool for onychomycosis.

BACKGROUND Onychomycosis is one of the most common nail disorders. Mycological examination by potassium hydroxide (KOH) mount and fungal culture is the most commonly used diagnostic method. However, it is associated with a low sensitivity. AIMS To evaluate the technique of subungual hyperkeratosis nail biopsy in diagnosing onychomycosis in HIV-infected and immunocompetent adults and compare it with mycological examination. METHODS 34 HIV-positive patients who presented clinically with onychomycosis were recruited in the study from the beginning. There was no screening done for patients with onychomycosis. This has been clarified in manuscript under the heading of methods. RESULTS All the fungal cultures yielded dermatophytes correlating with the biopsy findings. Only hyphal form of fungus was detected in KOH examination, indicating it was not a contaminant. Clinical types of onychomycosis are stated in discussion. CONCLUSIONS PAS stain of subungual hyperkeratosis nail biopsy was the most sensitive in the diagnosis of onychomycosis in both HIV-infected and non-infected groups.