Abstract

Dermatophytes are fungal pathogens that invade keratinised tissues, causing tinea infections named according to the site affected. Predominantly found in the genera Trichophyton, Microsporum, and Epidermophyton with Trichophyton being the most clinically significant. Diabetes mellitus, a chronic metabolic disorder with major public health implications, disrupts glucose, fat, and protein metabolism. Research on the association between glycemic status and dermatophytosis is limited. This study aimed to determine the prevalence of dermatophyte infections among diabetic patients in Lagos, Nigeria. In this cross-sectional study, 400 diabetic patients clinically diagnosed with dermatophytosis were recruited from two tertiary hospitals in Lagos State between August 2015 and February 2016. Microbial identification of dermatophytes involved conventional isolation, biochemical analysis, and polymerase chain reaction (PCR) targeting the internal transcribed spacer region, followed by gene sequencing.  Results showed that, Tinea pedis was the most prevalent infection (89.75%), followed by tinea capitis (6.25%) and tinea unguium (3%). Culture results showed no growth in 14% of samples, single isolates occurred in 45.25%, and multiple isolates occurred in 54.75% of the patients. Sixty isolates were presumptively identified as dermatophytes based on culture, but only 31 were confirmed molecularly. The primary etiological agents were Trichophyton interdigitale (42%), Trichophyton mentagrophytes (19%), and Arthroderma vespertilii (13%), followed by other Arthroderma species. This study identifies Trichophyton and Arthroderma species as the major dermatophytes causing infections in diabetic patients. Significantly, it is the first study to implicate Arthroderma species in dermatophytosis in Nigeria