[Rise of Trichophyton tonsurans in the period from 2008-2024 from a laboratory perspective-an emerging pathogen in...

Trichophyton (T.) tonsurans is an anthropophilic dermatophyte known as 'mat fungus' among wrestlers. Dermatomycoses caused by this pathogen have recently been diagnosed more frequently in Germany. A new route of infection is the transmission of T. tonsurans in barbershops. In this article, the laboratory diagnostic detection of T. tonsurans is assessed. Skin and hair samples, preferably from Saxony, Saxony-Anhalt and Thuringia and from all over Germany, were analysed. The mycological detection of T. tonsurans from skin scales, hair roots and swabs were based on culture methods. From 2011, diagnostics were supplemented by polymerase chain reaction-enzyme linked immunosorbent assay (PCR-ELISA). Selected dermatophyte strains were identified by sequencing the internal transcribed spacer (ITS) region of the ribosomal DNA in order to differentiate them from morphologically similar dermatophytes, in particular T. quinckeanum, which has also increased in prevalence during the period under investigation. From 2022, real-time (RT)-PCR with melting curve analysis was also used. Multiple isolates from one patient were only statistically considered once. If there were more than 3 months between two fungal detections, this was categorised as a new infection. For years, T. tonsurans was a rarely diagnosed dermatophyte. Until 2014, a maximum of 12 isolates were found per year. The detection rate rose to 20/year for the first time in 2015. A significant increase was observed from 2017 onwards. A significant increase was recorded from 2017 to 2019, with 38-71 cases of T. tonsurans annually. This was accompanied by a sustained outbreak of dermatophytosis caused by T. tonsurans at the Leipzig wrestling club. From 2020, there was an even more significant increase in T. tonsurans. The detection figures rose from 101/year to 347 in 2023. The provisional peak was reached in 2024 with 538 T. tonsurans infections. The increase is continuing. Two to three times more boys and men are affected than girls and women. The average age of patients is 15-20 years. The antimycotic treatment of tinea capitis, tinea barbae and tinea faciei should almost always be combined topical and systemic (oral). The drug of choice for oral treatment is terbinafine, but itraconazole is also effective. Fluconazole can also be used successfully in individual cases, especially as a powder for oral suspension as an alternative to tablets or capsules.