Onychomycosis: Clinical findings, etiological agents and evaluation of laboratory methods

Abstract

The aim of this study was to identify the etiological agents in patients with suspected onychomycosis, and to carry out comparative testing of individual or combinations of tests: direct microscopy with KOH and Blankophor (BP), culturing on Sabouraud's dextrose agar (SDA), diluted Sabouraud's dextrose agar (D-SDA) and dermatophyte test medium (DTM). From 70 nail samples (65 toenails, 5 fingernails), 46 (60.5%) had at least one of five positive tests. Isolation was possible in 41, while in 5 samples the presence of fungi was observed by KOH and/or BP. Dermatophytes were most frequently isolated (80.5%) where Trichophyton rubrum was predominant. Candida spp. was isolated in 9.8%, Aspergillus spp. 4.9%, Alternaria spp. 2.4% and Fusarium spp. 2.4%. Application of BP as an individual test was the most sensitive method. The combination of BP with DTM or D-SDA provides the best sensitivity and allows the identification of fungi to the species/genus level.