Sensitivity of PAS histopathology stain for the diagnosis of onychomycosis at multicenter teaching hospitals, Pakistan.
The aim of this study was to determine the sensitivity of Periodic acid –Schiff (PAS) staining an early and quick effective diagnostic test of nail clipping with routine tests in the diagnosis of Onychomycosis. Background: The routine gold standard for diagnosis of fungal nail infections has been direct microscopy (KOH mount) and mycological culture which often yield delayed or weak/false negative results. However recent studies have suggested that nail plate biopsy using PAS stain is rapid method of detection that grasped the diagnosis and manage the disease. Study Design: Cross sectional descriptive study. Setting: 320 clinical diagnosed cases of onychomycosis performed at Department of Microbiology, Quaid-e-Azam Medical College Bahawalpur and Department of Histopathology King Edward medical University Lahore. Period: January 2012 to August 2018. Materials and Methods: The parameter looked in the sent investigation were histopathology PAS stain, mycological culture and microscopy. Presences of intensely stained reddish dots or threads like structures in between the cells of nail plate were considered to be positive results on histopathology with periodic acid Schiff (PAS). The microscopic study showed hyphae or spores and growth of organism concluded by morphological colony characteristics on Sabouraud's dextrose agar (SDA) periodically after 4 weeks. Result: out of total 320 cases, 81.25% was positive for histopathology PAS stain. Culture positivity was 60% and KOH mount recovered 52.5% positive. The combination of PAS stain and culture results showed 90.62% while Culture and KOH were 62.5% in nail clipping specimen. Conclusion: Histopathological PAS technique was found to be more effective than other laboratory methods for the diagnosis of Onychomycosis.