Clinicomycological study of dermatophytosis in a tertiary care centre

Background: Fungal infections constitute a major health problem all over the world. Signs and symptoms induced by various dermatophytic infections are hardly distinguishable clinically from each other. Hence, characterisation by in vitro culture is required for the appropriate diagnosis and treatment as well as for studying the epidemiological characteristics in a region. Objectives: The objectives of this study are: (1) To isolate and identify dermatophytes affecting skin and nail. (2) To compare two different culture media, namely Sabouraud′s dextrose agar (SDA, Himedia Laboratories, Mumbai) with Chloramphenicol and Actidione with dermatophyte test medium (DTM, Hi-Media Laboratories). Materials and Methods: This is a cross-sectional study in which patients attending the outpatient wing of the Department of Dermatology and Venereology, Government Medical College, Thiruvananthapuram, Kerala, India, with clinical features of dermatophytosis were included from March 2011 to February 2012. Skin and nail scrapings were subjected to direct microscopy by 10% potassium hydroxide (KOH), 40% KOH and cultured on SDA with Actidione (Hi-Media Laboratories) and DTM (Hi-Media Laboratories). Results: The total number of samples in this period was 150, of which 99 (66%) samples were positive by direct microscopy and 74 (49.33%) were positive by culture. The most common clinical type was tinea corporis 75 (50%) followed by tinea cruris 40 (26.67%). Out of the 74 isolates, Trichophyton rubrum 40 (54.05%) was the most common species followed by Trichophyton mentagrophytes 29 (39.19%), Microsporum gypseum three (4.05%), Trichophyton schoenleinii one (1.35%) and Epidermophyton floccosum one (1.35%).Nearly 86.1% of the dermatophytes were isolated on DTM within 5-10 days of inoculation whereas 47.05% were isolated on SDA within 10 days of inoculation. This was statistically significant with P < 0.0001 (χ2 = 22.43). Conclusion: DTM can be used as a rapid screening medium for the isolation and identification of dermatophytes compared to SDA with Actidione. However, DTM is inferior to SDA with Actidione in the identification of dermatophyte species.