[Investigation of the agents and risk factors of dermatophytosis: a hospital-based study]

Abstract

The aims of this study were the detection of distribution of dermatophyte species isolated from the clinical samples of patients with dermatophytosis and the evaluation of risk factors for the development of dermatophytosis. A total of 441 skin, nail and scalp/hair specimens obtained from 301 patients (151 were male; age range 2 months-80 years, median 42 years) and 884 foot and hand skin and nail specimens obtained from 221 control subjects (110 were male; age range 5-75 years, median 36 years) were included to the study between the period of January to December 2005. All the samples have been evaluated by direct microscopic (DM) examination and by culture. A total of 121 (40.2%) patients yielded positivity for dermatophytes, of them 63 were positive by both DM and culture methods, seven were only culture positive, and 51 were only DM positive. Nine (9.8%) of 92 culture positive samples from 70 patients were found negative in DM, while 85 (50.6%) of 168 DM positive samples from 114 patients were negative in culture. 23.5% (12/51) of DM positive but culture negative patients were given antifungal therapy previously. The most prominent species isolated from the cultures were Trichophyton rubrum with a rate of 68.4% (63/92), followed by T. mentagrophytes (18.4%); T. violaceum (3.3%); T. verrucosum, T. tonsurans and Epidermophyton floccosum (2.2% for each); T. schoenleini, Microsporum canis and Trichophyton sp. (1.1% for each). Of the patient samples whose cultures were positive, 45% were from the foot skin. The presence rate of dermatophytes in controls was found as 3.2% (7/221); T. rubrum was isolated from the foot skin of five and T. mentagrophytes was isolated in toenail of two control subjects. About 42% of the samples belonged to the patients who admitted to hospital between December to February period. The evaluation of the risk factors revealed that presence of trauma, pet contact, ritual cleansing and diabetes mellitus had no effect on the development of dermatophytoses, however the presence of fungal infection in the family, male gender, some professions (being farmer, worker and retired), and the use of immunosupressive drugs have been found to increase the risk of dermatophytosis. The number of cases with dermatophytoses started to increase beginning from the age of 20 and peaked in the ages between 40-59 years old. As a result T. rubrum was determined as the most frequently isolated dermatophyte and tinea pedis was the most frequently observed clinical form in our hospital, emphasizing the importance of early diagnosis and effective treatment in superficial fungal infections which have high morbidity.