Trichophyton mentagrophytes Genotype VII and Sexually Transmitted Tinea: An Observational Study in Spain.

Background: In 2019, Trichophyton mentagrophytes genotype VII (TMVII) was identified in Germany as a cause of sexually transmitted tinea. Since 2023, it has been described in men who have sex with men (MSM) in France, Italy, and the United States. No cases have been reported in Spain.

Obectives: Our study aimed to assess the occurrence of TMVII in an STI clinic in Barcelona.

Patients/methods: We identified TMVII cases among all positive mycological skin/hair cultures between January 2020 and January 2025 by sequencing the internal transcribed spacer on isolates of T. mentagrophytes-interdigitale. We retrospectively collected demographic, clinical and treatment data and analysed the association between treatment received and outcome (cure vs. recurrence).

Results: Among 21 positive cultures, we obtained 15 isolates of T. mentagrophytes-interdigitale, of which 14 were sequenced and identified as TMVII. Patients with TMVII were all MSM; most were HIV positive (7) or negative on preexposure prophylaxis (6). Main sites of infection were pubogenital (6), buttocks-perianal (5) and beard (2). Six patients required multiple courses of treatment due to recurrence. Twenty-one courses of antifungal therapy were analysed, with an observed cure rate of 45% (5/11) for oral terbinafine vs. 80% (7/10) for topical agents (p = 0.39), and 0% (0/6) for ≤ 2-week courses vs. 80% (12/15) for 3-to-8-week courses (p < 0.01).

Conclusions: Our study confirms the presence of TMVII in Spain, supporting its circulation across Europe. Epidemiological profile and site of infection support sexual transmission. Patients responded to systemic or topical terbinafine but required longer-than-usual periods of treatment.