Epidemiological survey of 32,786 culture-positive dermatophytosis cases in Hangzhou from 2018 to 2023

Background: With the rapid development of the economy and changes in lifestyle in recent years, the epidemiological pattern of dermatophytosis has changed. We analyzed the epidemiological features of dermatophytosis in a hospital in Hangzhou from 2018 to 2023.

Methods: Data from patients with culture-positive dermatophytosis were obtained from the Laboratory Information System of the Mycology Laboratory of our hospital. Dermatophyte isolates were mainly identified by macroscopic and microscopic features of the colonies.

Results: There were 32,786 patients with culture-positive dermatophytosis during the 6-year period, including 16,789 male patients and 15,990 female patients. Patients' ages ranged from 1 month to 97 years. Tinea unguium accounted for the largest proportion (14,879, 45.38%), which was mainly prevalent among females (8946, 60.13%). Significant gender differences were observed in all clinical types of dermatophytosis, except for tinea pedis. In total, 15,486 (47.73%) patients aged 21-40 years. The median age of patients with tinea manum and tinea capitis was the highest (49 years) and the lowest (5 years), respectively. Nine species of isolated dermatophytes were identified, of which Trichophyton rubrum accounted for 90.20% (29,573 cases). M. canis accounted for 66.80% of isolated dermatophytes from tinea capitis. The isolation rates of zoophilic species were 43.41% in tinea faciei and 18.90% in tinea corporis.

Conclusion: T. rubrum was absolutely predominant agent of dermatophytosis except tinea capitis in which M. canis was the most common organism. The prevalence of zoophilic dermatophytes has increased in tinea faciei and tinea corporis. Tinea unguium was the major clinical form of dermatophytosis, and it was more prevalent among females. The onset peak of dermatophytosis was in the age group of 21-40 years, except for tinea capitis.