Supplementary Material for: Trichophyton violaceum: An Emerging Pathogen in Southern Switzerland

Background: Trichophyton violaceumis an anthropophilic dermatophyte, endemic in Africa and recently an emerging pathogen in Europe. Objective: To perform a retrospective analysis of dermatophytoses due to T. violaceum between 2007 and 2018, in order to evaluate epidemiological trends in Southern Switzerland (Ticino). Methods: We reviewed all medical records of patients affected by dermatophytosis due to T. violaceum between January 2007 and December 2018 in Bellinzona (Ticino, Switzerland). Results: Dermatophytoses due to T. violaceumwas diagnosed in 44 patients, 33 of which were in the last 4 years. The most affected sex was female (25/44) and the most frequent diagnosis was tinea capitis (30/44). The majority of tinea capitis patients were children younger than 13 years of age (27/30). The main source of contagion were people from endemic areas, especially from Eritrea. Conclusion: In Southern Switzerland T. violaceumhas been rarely diagnosed before 2014. Its increased occurrence seems linked to increased migratory flows from Eritrea. Since it is responsible mainly for tinea capitis, with most of the time no clearly defined alopecia patches, it is important to consider it as a possible diagnosis when facing scalp scaling. Tinea capitis due to T. violaceum is a benign affection, but if left untreated it can spread epidemically, especially among children in schools and kindergartens. Mycological examination is then required, not only for a correct diagnosis and epidemiological data, but also for planning the appropriate treatment.