Onychoscopy: a quick and effective tool for diagnosing onychomycosis in a resource-poor setting

Onychomycosis is the most prevalent nail disease. Although clinical diagnosis of onychomycosis is easy, fungal culture as a confirmatory test requires an equipped laboratory and is time-consuming. Onychoscopy is a simple, quick, and inexpensive technique and may help clinicians increase the diagnostic accuracy of onychomycosis. The aim of this study was to identify common onychoscopic patterns of onychomycosis and correlate them with clinical subtypes of onychomycosis.

This study was performed in the dermatology outpatient department of a tertiary care hospital in northern India for 6 months. Clinically diagnosed cases of onychomycosis were confirmed by potassium hydroxide (KOH) mount. After obtaining informed written consent, these patients underwent onychoscopy with DermLite II hybrid m, 3Gen, polarized mode, 10× magnification. The common onychoscopic patterns were recorded and the data analyzed.

The study included 60 confirmed cases of onychomycosis. The common onychoscopic patterns observed were jagged edges with spikes of the onycholytic area in 65.5% of cases, longitudinal striae in 77.6%, distal irregular termination or a "ruin pattern" in 82.7%, and chromonychia in 62.1%. Clinical types of onychomycosis showed a statistically significant association with chromonychia (p = 0.000), jagged edges with spikes (p = 0.015), and distal irregular termination (p = 0.016).

Onychoscopy can be a complementary tool in clinical diagnosis of onychomycosis to alleviate the need for direct microscopy and culture.