Clinico-mycological correlation in onychomycosis in a tertiary level hospital

ABSTRACT

To correlate the clinical patterns of onychomycosis with the type of mycological agents in onychomycosis. In this cross-sectional study, 120 patients with onychomycosis, attending outpatient department, were selected by purposive type of sampling technique. They were subjected to thorough clinical examination. Nail material was collected for mycological diagnosis by microscopy and culture on dermatophyte test medium. Microscopy was positive in 47 [39.2%] cases, whereas culture yielded Trichophyton rubrum in 53 [44.2%] and T. mentagrophytes in 2 [1.7%] patients. Common clinical nail changes in mycologically proven cases were thickening of nail plate [68.9%], subungual hyperkeratosis [63.9%], onycholysis [55.7%], roughening of nail plate [29.5%], yellowish discoloration [29.5%] and brownish-yellow discoloration [21.3%]. Only, subungual hyperkeratosis was found significantly more in mycologically positive cases [63.9%] than in mycologically negative cases [37.3%], p<0.05. The validity of microscopic examination for prediction of onychomycosis revealed sensitivity [74.5%], specificity [90.8%], accuracy [83.3%], positive predictive values [87.2%] and negative predictive values [80.8%]. There is an insignificant correlation between clinical pattern and mycological diagnosis. No single clinical feature is suggestive of onychomycosis, hence, direct microscopy must always be coupled with fungal culture for accurate diagnosis.