O07 Clinical and mycological profile of dermatophyte infections in England
Authors: Khanh Linh Phan, David Chandler
Journal: British Journal of Dermatology (2024)

Abstract The aim of this study was to provide an update on the epidemiology and causative agents of dermatophyte infections in England. We analysed all samples of skin, hair and nail (n = 34 624) that underwent mycological examination (microscopy and culture) in a single diagnostic microbiology laboratory in South East England over a period of 17 years (2006–2023). Fungal culture was positive for 22.0% (n = 7601) of samples. Dermatophytes accounted for 89.4% (n = 6793) of these, and nondermatophyte moulds were isolated in 4.8% (n = 366). The dermatophyte most commonly isolated was Trichophyton in 99.3% (n = 6744), followed by Microsporum in 0.5% (n = 37) and Epidermophyton in 0.2% (n = 12). Within the Trichophyton group, 99.4% (n = 6703) were pure Trichophyton isolates, while 0.6% (n = 41) displayed a mixed growth of dermatophyte and nondermatophyte moulds. Onychomycosis of the toenails was the most common infection (n = 2472), predominantly affecting women, with a mean age of 48.3 years. Trichophyton rubrum was isolated in 82.7% of cases, with positive micro­scopy (fungal hyphae observed) in 44.5%. Onychomycosis of the fingers, while less frequent (n = 427), exhibited a similar demographic profile, affecting mostly women, with a mean age of 53.7 years. Other dermatophyte infections included tinea pedis (n = 400), tinea corporis (n = 204), ­tinea cruris (n = 90), tinea manuum (n = 58) and tinea faciei (n = 14). Trichophyton rubrum was the ­commonest cause of ­dermatophyte infection across all body sites, except for tinea capitis (n = 82), where Trichophyton mentagrophytes (30.5%), Trichophyton violaceum (19.5%) and Trichophyton tonsurans (15.9%) were the most common causative agents. Non-anthropophilic species (n = 158) caused infection across all body sites, although most commonly this manifested as tinea capitis (25.3%, n = 40) or tinea corporis (20.3% n = 32). Notably, these infections were found to occur in a younger age group, with 27.8% of cases in individuals &amp;lt; 10 years old, and were more common in female patients. Trichophyton mentagrophytes, a zoophilic dermatophyte, was the most prevalent non-anthropophilic species in this study. Over the 17-year period (2006–2023), T. ­mentagrophytes, Microsporum canis and T. tonsurans showed significant declines in prevalence of 95%, 90% and 86%, respectively. Conversely, T. rubrum, constituting 75% of all dermatophytes isolated in 2006, demonstrated a substantial increase, reaching a prevalence of 95% in 2023. There were no cases of Trichophyton indotineae. This study provides an overview of recent epidemiological trends in dermatophyte infections in England. Trichophyton rubrum is increasingly the commonest cause of dermatophytosis, and the nails are the most common site of infection. Infection with non-anthropophilic species is rare and has a distinct demographic profile. Awareness of local trends in the clinical and mycological profiles of dermatophyte infections is important to guide the management of individual cases and inform public health interventions.