Comparison of direct microscopic methods using potassium hydroxide, periodic acid Schiff, and calcofluor white with culture in the diagnosis of onychomycosis

In fluorescent microscopy, KOH treated nail material was stained with fluorescent brightener, CW, on a glass slide and fungal elements were examined under fluorescent microscope. Considering culture as gold standard, sensitivity, specificity, positive predictive value, and negative predictive value were calculated for each microscopic method. [...]the present study shows that CW microscopy gives significantly higher rates of detection of onychomycosis compared to the other microscopic methods using KOH and PAS stain.