Objective: To compare the diagnostic yields of KOH mount and PAS staining of nail clippings for demonstration of hyphae.
Study Design: Cross sectional study.
Place and Duration of Study: Study was conducted at dermatology department, POFs’ Hospital Wah Cantt. The duration of the study was one year, from Aug 2016 to Aug 2017.
Material and Methods: The sample size of 60 patients was calculated using WHO calculator. Non probability consecutive sampling was used for recruitment of participants. Patients of any age and of either sex with clinical suspicion of onychomycosis were included in the study. Nail clippings of affected nails of each subject were examined for hyphae after KOH mount and PAS staining. SPSS software was used for data analysis. Chi-square test and ROC curve analysis were used for diagnostic accuracy measurement.
Results: Out of sixty patients, hyphae were seen in 49 (81.66%) after PAS staining and in 19 (31.66%) after KOH mount. PAS staining is found to be more sensitive (80.3%) for diagnosis of onychomycosis as compared to KOH (29.4%) (p=0.02). ROC curve analysis showed PAS had good diagnostic accuracy (ROC curve area=0.80) while KOH had poor diagnostic accuracy (ROC curve area=0.60).
Conclusion: PAS staining of nail clippings for hyphae is a very sensitive method for diagnosis of nychomycosis as compared to KOH mount. The current gold standard needs to be reviewed.
Keywords : KOH mount, Nail clippings, Onychomycosis, PAS staining.