Clinico-Mycological Study of Dermatophyte Toenail Onychomycosis in New Delhi, India

INTRODUCTION: There is a constant need to define the epidemiological and mycological characteristics of onychomycosis (OM) for optimal management strategies. OBJECTIVES: To define the epidemiological and mycological characteristics of patients with dermatophyte toenail OM in a tertiary care hospital. MATERIALS AND METHODS: Hundred consecutive patients of KOH and culture-positive dermatophyte toenail OM were subjected to detailed history, clinical examination and investigations. RESULTS: Maximum number of patients (40%) belonged to 31-45 years age group and there was a male preponderance (M:F = 6.7:1). The mean duration of disease was 54 months. Thirty-three patients had fingernail involvement in addition to the toenail OM and 37% had co-existent cutaneous dermatophyte infection. Discoloration was the most common symptom (98%). Ninety-four (94%) patients had distal lateral subungual onychomycosis (DSLO) while two had superficial onychomycosis (SO) and only one had proximal superficial onychomycosis (PSO). Trichophyton interdigitale was the most common etiological agent (61%) followed by Trichophyton rubrum and Trichophyton verrucosum. CONCLUSIONS: Toenail OM is more common in males. DSLO was the most common clinical variant and T. interdigitale the most common etiological fungus responsible for toenail OM in our region. The importance of early diagnosis and treatment is highlighted as long-standing toenail OM predisposes to fingernail onychomycosis and recurrent tinea pedis.