Onychomycosis is a fungal infection of the finger or toe nail caused by various fungal agents like dermatophytes, non dermatophytes moulds and yeasts. It is necessary to diagnose the infection with proper laboratory evidences before treating them with antifungal drugs, which require prolonged duration of treatment and may have adverse side effects. This study involves comparison of standard laboratory tests in the diagnosis of onychomycosis, namely, potassium hydroxide mount (KOH mount), Calcofluor white staining and fungal culture of the nail clippings. A total of 100 patients with clinically suspected onychomycosis were selected. Nail scrapings and clippings were subjected to KOH mount, Calcofluor staining for direct microscopic examination and culture using Sabouraud’s dextrose agar. Out of the 100 patients, direct microscopy with KOH mount, calcofluor mount and fungal culture showed positive results in 69(69%), 80(80%), 54(54%) respectively. Out of the 54 culture positive 29 were Dermatophyte, 20 were non dermatophytes mould (Aspergillus) and 5 were Candida species. Culture was taken as the gold standard and was compared with KOH mount and calcofluor white microscopy. The sensitivity and specificity of KOH microscopy was and respectively, whereas calcofluor white microscopy showed and respectively. Calcofluor white is the best method to detect fungal agents from clinically suspected onychomycosis cases with high sensitivity. It is easy to perform, rapid, and give significantly higher rates of detection of onychomycosis compared to the KOH mount and fungal culture. | Comparison of KOH, calcofluor white and fungal culture in the diagnosis of onychomycosis
