Epidemiological trends of dermatophytosis in Tehran, Iran: A five-year retrospective study

Dermatophytosis is the most frequent fungal infection all over the world and its frequency is constantly increasing. The aim of this study was to evaluate clinical features and epidemiological trends of dermatophytosis over the years 2010 to 2014 in Tehran, Iran.

A total of 13,312 patients clinically suspected of cutaneous fungal infections were examined. Skin scales, plucked hairs, nail clippings and sub-ungual debris were examined by direct microscopy and culture. Dermatophyte species were identified at the species level by a combination of morphological and physiological criteria.

Direct microscopy confirmed a contamination rate of 19.7% (2622/13,312 cases) of which 1535 cases (58.5%) were culture positive distributed in male (1022 cases) and female (513 cases). The most commonly infected age group was the 30-39 years old. Tinea pedis (30.4%) was the most prevalent type of dermatophytosis followed by tinea cruris (29.8%) and tinea corporis (15.8%). Epidermophyton floccosum (31%) was the most prevalent causative agent, followed by Trichophyton rubrum (26.2%) and Trichophyton mentagrophytes (20.3%).

Our results showed considerable distribution of dermatophytosis from zoophilic, anthropophilic and geophilic species among population with diverse age groups. Although anthropophilic fungi such as T. mentagrophytes, E. floccosum, and T. rubrum were the main etiologic agents of dermatophytosis, the prevalence of T. verrucosum showed a meaningful increase over the years, which highlights the importance of rural dermatophytosis mainly transmitted from large animals. This noticeable information improves our current knowledge about dermatophytosis and assists to establish effective prevention and therapeutic strategies to overcome the disease.