Clinical Features and Skin Microbiome of Tinea Scrotum: An Observational Study of 113 Cases in China

Background The scrotum is considered as an uncommon site for tinea, hence there is a lack of knowledge about the clinical characteristics, pathogenic agents and the skin microbiome changes of tinea scrotum. Objective We sought to analyze the clinical features, pathogenic agents and skin microbiome of tinea scrotum. Methods A two-center prospective observational study was carried out in outpatient dermatology clinics in Zhejiang, China, from September 2017 to September 2019. The diagnosis of tinea scrotum was confirmed by direct microscopy. Clinical and mycological data were collected. The composition of microbial communities of patients with tinea scrotum was analyzed and compared with healthy controls. Results A total of 113 patients with tinea scrotum were included. Tinea scrotum was either presented with isolated lesions (9/113, 8.0%) or accompanied by tinea of other sites (104/113, 92.0%). Tinea cruris was detected in 101 cases (89.38%). Fungal culture was positive in 63 cases, among which Trichophyton rubrum was grown in 60 cases (95.2%) and Nannizzia gypsea was cultured in 3 cases (4.8%). The skin microbiome in scrotum lesions from 18 patients showed increased abundance of Trichophyton compared with 18 healthy individuals, while Malassezia was decreased. No significant difference in bacterial diversity was found. Conclusions Tinea scrotum was often companied by superficial fungal infections of other skin sites, with tinea cruris being the most common condition. Instead of N. gypsea , T. rubrum was the most frequently identified pathogen for tinea scrotum. In general, tinea scrotum exhibited changes in the fungal communities of the skin with increased Trichophyton and decreased Malassezia abundance.