Factors in Etiology and Predisposition of Adult Tinea Capitis and Review of Published Literature

Background Tinea capitis is a common fungal infection in children but is less frequently encountered in adults, especially in immunocompromised individuals. Objectives To determine the incidence of tinea capitis in adults, the predisposing factors and causative species. Methods A retrospective study was conducted over a period of 5 years, from 2010 to 2015, on cases of tinea capitis diagnosed in the Department of Dermatology and Mycology Research Center in Tehran, Iran. The information was collected from the patients including age, gender, location of the lesions, results of direct examination and culture, cause of immunosuppression and the prescribed treatment. Results Twenty-five (20.6 %) patients (10 men and 15 women) with a mean age of 45.28 years were affected by tinea capitis among a total number of 121 positive cases. Most of these adults (80 %) had a grade of immunodeficiency due to the underlying syndromes or diseases, and the rest were immunocompetent. Trichophyton species were isolated from 84 % of these adult patients, indicating Trichophyton violaceum ( T. violaceum ) as the most common fungal agent. Treatment with oral terbinafine or itraconazole was successful in all these cases. Conclusions The results showed that most cases affecting the adult population were caused by species of the genus Trichophyton . T. violaceum was the most common dermatophyte of adult patients. Thus, it is important to consider tinea capitis as a differential diagnosis in immunocompromised adults, even though it is considered to be rare in adults.