EVALUATION OF KOH MOUNT, FUNGAL CULTURE, AND PAS STAINING IN ONYCHOMYCOSIS: A COMPARATIVE STUDY

Onychomycosis is a prevalent condition linked to considerable physical and psychological morbidity.  The rise in prevalence in recent years can be linked to increased longevity, comorbid conditions such as diabetes, active participation in certain activities, and the emergence of HIV.  The study aimed to assess the efficacy of KOH mount, fungal culture, and PAS staining of the affected nail plate in diagnosing onychomycosis.  Approach:  One hundred ten patients with clinically suspected onychomycosis were selected for the study.  Nail scrapings and clippings underwent KOH mount for direct microscopic examination, culture on Sabouraud’s dextrose agar (with and without antibiotics), and histopathologic examination utilising PAS staining (HP/PAS).  Results: Direct microscopy with KOH mount, mycological culture, and HP/PAS yielded positive results in 40 (36.36%), 35 (31.81%), and 45 (40.90%) patients, respectively.  Fungal infection was confirmed in 45 samples using at least one of the three methods.  When using this as the denominator, HP/PAS exhibited a sensitivity of 40.90%, which was significantly greater than that of KOH mount (36.36%) or mycological culture (31.81%).  In conclusion, histopathologic diagnosis utilising PAS staining of nail clippings demonstrated the highest sensitivity among the tested methods.  The procedure was straightforward, efficient, and resulted in markedly higher detection rates of onychomycosis compared to standard methods, specifically KOH mount and mycological culture.