TMVII: Understanding the Emerging Sexually Transmitted Fungus & Diagnosis

The emergence of a sexually transmitted fungal infection, Trichophyton mentagrophytes genotype VII (TMVII), is prompting increased vigilance among clinicians, particularly as cases can mimic more common skin conditions like eczema or bacterial infections. Recent reports, including an outbreak in Minnesota, highlight the need for awareness and accurate diagnosis. While treatable, the infection’s ability to present atypically can lead to delays in appropriate care.

Minnesota reported what it described as the country’s largest known outbreak of TMVII last month, according to a report. The infection manifests as round, coin-like rashes that are red and irritated, sometimes with bumps, and pimples. These rashes can appear on the face, buttocks, genitals, arms, legs, and abdomen, and can potentially lead to scarring or secondary infections if left untreated. Fortunately, It’s generally responsive to oral antifungal medications.

Diagnostic Challenges and Clinical Presentation

The first U.S. Case of TMVII was identified in New York City in 2024, and Minnesota’s first case was diagnosed in July 2025. The fungus has been circulating in Europe for several years, often linked to individuals who engaged in sex tourism in Southeast Asia. The Centers for Disease Control and Prevention (CDC) notes that TMVII tends to be more prevalent among men who have sex with men. However, it’s crucial to remember that anyone can contract the infection through sexual contact.

Avrom S. Caplan, MD, associate professor of dermatology at NYU Grossman School of Medicine, emphasizes the diagnostic hurdles. “Tinea infections can mimic eczema, psoriasis, and bacterial skin infections,” he explained in an interview with Healio. “Sometimes people have an itchy rash and get topical steroids, which can mask the classic features of tinea. When tinea goes into a hair follicle, it can start to look atypical.” This can lead to misdiagnosis and delayed treatment.

Dr. Caplan too noted that the infection can be particularly tricky to diagnose as it often presents as a genital rash, which is not typical for most tinea infections. He recommends clinicians consider tinea in their differential diagnosis when evaluating sexually active patients with genital rashes, even if those rashes appear atypical.

What Makes TMVII Different?

One of the key challenges with TMVII is its potential to be confused with other conditions. Bacterial folliculitis and even syphilis can present with similar symptoms. Dr. Caplan stresses the importance of considering syphilis in the differential diagnosis, particularly when a rash is present and there is a possibility of sexual transmission. He recommends testing for syphilis alongside TMVII to ensure a comprehensive evaluation.

The diagnostic process can be further complicated by the fact that bedside tests for fungal infections aren’t always precise, and cultures can take time to yield results. If a patient isn’t responding to treatment for a presumed condition like eczema or psoriasis, clinicians should reconsider the possibility of a tinea infection and potentially consult a dermatologist.

Treatment and Prevention Strategies

While specialized molecular testing can confirm a TMVII diagnosis, treatment can often be initiated empirically with topical or oral antifungals. Dr. Caplan notes that TMVII is not currently known to be resistant to standard antifungal medications. However, treatment can take time, especially if the infection has been present for a while or if the patient has used topical steroids.

Preventing the spread of TMVII relies heavily on education and early treatment. Clinicians should discuss ways to minimize transmission during the treatment period with their patients. We find also reports suggesting a potential period of asymptomatic spread, meaning someone could transmit the infection before they develop symptoms, adding another layer of complexity to prevention efforts.

Public Health Response and Ongoing Monitoring

The recent cluster of cases in Minnesota has prompted increased awareness and monitoring efforts. Public health officials are working to disseminate information to clinicians and the public about TMVII, its symptoms, and appropriate treatment. Dermatologists are being urged to remain vigilant and consider TMVII in their differential diagnosis when evaluating patients with suspicious rashes.

The CDC is also monitoring the situation closely and may issue further guidance as more information becomes available. Ongoing surveillance is crucial to track the spread of TMVII and identify any emerging trends. The CDC emphasizes the importance of confirming fungal diagnoses before prescribing antifungals, which can help prevent the development of resistance.

As awareness of TMVII grows, it’s likely that more cases will be identified. Continued education of both clinicians and the public will be essential to mitigate the spread of this emerging sexually transmitted fungal infection. Individuals experiencing unusual rashes, particularly in the genital area, should seek medical attention for accurate diagnosis and appropriate treatment.

Avrom S. Caplan, MD, can be reached at [email protected].