Minnesota’s TMVII outbreak puts a spotlight on sexually associated ringworm: what people should know

The practical takeaway: if you have a persistent rash on the groin, genitals, buttocks, thighs, lower abdomen, or nearby skin, do not keep guessing at it, especially if it is painful, spreading, or not improving. Minnesota health officials said on February 11, 2026 that the state has the largest known U.S. outbreak of TMVII, an emerging type of ringworm linked to sexual or other intimate skin-to-skin contact. In suspected cases, testing and prescription treatment may matter more than usual.

The Minnesota Department of Health said more than 30 confirmed or suspected cases have been reported in the Twin Cities metro area since July 2025. That does not mean TMVII is suddenly a widespread national outbreak. But it is a clear signal that clinicians and patients may need to think differently about certain stubborn rashes.

What TMVII is, and why it is getting attention now

TMVII stands for Trichophyton mentagrophytes genotype VII. It is a dermatophyte, which means a fungus that causes tinea, commonly called ringworm. Ringworm is not a worm.

What makes TMVII different from the usual mental picture of ringworm is the way it has been showing up. Health agencies say it has been linked to sexual or intimate skin-to-skin contact, especially in recent case reports and outbreaks among men who have sex with men. That does not make it a conventional sexually transmitted infection in the same sense as gonorrhea or syphilis. It is still a fungal skin infection, but one that can spread during close physical contact.

It is also important not to mix TMVII up with another emerging issue: antifungal-resistant ringworm. The CDC says TMVII is usually not antimicrobial-resistant. Even so, it may still need a longer course of prescription oral antifungal medicine than ordinary ringworm.

What the rash can look like, and where it often shows up

Based on Minnesota and CDC guidance, reported TMVII rashes have often involved the genitals, skin around the anus, buttocks, groin, thighs, abdomen, and sometimes the face. The rash may be:

itchy
painful or tender
persistent
red or irritated
scaly and sharply bordered
bumpy or pustular, meaning it can have pimple-like or pus-filled spots

Some people may expect ringworm to look like a classic round patch on an arm or leg. TMVII can look more inflamed than that, and the location of the rash can make people assume it is something else.

Why TMVII may be missed or mistaken for something else

This is one of the biggest public-service points in the Minnesota advisory: TMVII can be mistaken for other conditions. Health officials say the rash may resemble eczema, psoriasis, or other skin infections. In the genital or groin area, it can also raise concern for a sexually transmitted infection.

That matters because delayed recognition can keep symptoms going longer and may increase the chance of spread. A 2025 Emerging Infectious Diseases report highlighted that TMVII may be confused with psoriasis and other sexually transmitted infections, and that delayed treatment can lead to scarring, secondary bacterial infection, and continued spread.

That report is worth understanding in context. It was not a national surveillance study or a treatment trial. It was a small, hypothesis-generating poll of 117 U.S. infectious-disease clinicians. Its value is not that it tells us how common TMVII is nationwide. Its value is that it suggests clinician familiarity is still limited, which helps explain why some cases may be missed at first.

The bottom line for readers is simple: not every genital, groin, or buttock rash is fungal, but not every one is an STI either. If the rash may be related to intimate contact, tell the clinician that detail. It can change what they consider, what they test, and how they treat it.

Why testing matters

Ordinary ringworm is often diagnosed by appearance alone. But when TMVII is suspected, visual diagnosis may not be enough.

Minnesota health officials advised clinicians to confirm a dermatophyte infection with KOH microscopy when available. That is a quick lab method in which a skin scraping is treated with potassium hydroxide and examined under a microscope for fungus. For suspected TMVII, they also advised fungal culture of skin scrapings, and in some cases biopsy, followed by confirmatory typing or genotyping of the fungal isolate.

The American Academy of Dermatology also notes that dermatologists may scrape a small bit of skin, hair, or nail and send it to a lab to confirm ringworm.

This testing message is especially important because fungal skin infections are often treated without confirmatory lab work in everyday practice. A January 2026 Medical Mycology study looked at routine tinea corporis and tinea cruris care in a large U.S. Medicaid population of 6.8 million patients. It was an observational claims-based study, not a TMVII study, and it cannot tell us how TMVII behaves. Still, it offers useful context: confirmatory testing for everyday ringworm is not common. TMVII is one of the situations where more careful testing may be more important than usual.

Why treatment may differ from routine self-care

Many people think of ringworm as something to treat with an over-the-counter cream and forget about. That may work for common, limited ringworm. TMVII can be different.

The CDC says sexually associated ringworm may require oral antifungal medication for several weeks or months. Minnesota advised clinicians that suspected TMVII often should be treated with oral terbinafine rather than waiting for confirmatory results, with treatment generally lasting six to eight weeks and sometimes up to 12 weeks. Topical treatment alone may not be enough.

That does not mean every rash that fails over-the-counter treatment is TMVII. It does mean that treatment failure is a reason to get evaluated instead of just trying more products.

One especially important warning: do not keep putting steroid creams on an unexplained rash unless a clinician tells you to. Both the CDC and Minnesota health officials warn that steroid creams can worsen TMVII. Combination creams that include both an antifungal and a steroid can also be a problem.

What readers can do right now

Seek care if a rash in the groin, genital, buttock, thigh, abdominal, or nearby area is painful, spreading, sharply bordered, pustular, or not improving.
Tell the clinician about intimate contact if you think the rash may be related to sexual or close skin-to-skin exposure.
Avoid sexual or other skin-to-skin contact with a suspicious rash until you have been evaluated and treated.
Do not share towels, bedding, clothing, razors, or similar personal items.
Wash clothing and linens on high heat if ringworm is suspected.
Avoid steroid creams on an unexplained rash unless a clinician specifically recommends them.
Encourage partners with symptoms to get checked rather than self-treating in the dark.

What is still uncertain

Minnesota is the clearest outbreak signal right now, but it is not proof that TMVII is common nationwide. State officials said the CDC is aware of sporadic U.S. cases outside Minnesota, mainly in larger cities. That tells us TMVII is not limited to one place. It does not tell us how widespread it is in the general population.

There is also still a lot to learn about how often it is misdiagnosed, how much unnoticed spread may be happening, and how often partners without symptoms may carry or develop infection later.

What this means for readers: a stubborn rash in intimate areas is not something to keep guessing at. Ringworm is a fungal infection, and some newer forms linked to intimate contact may need lab testing and prescription pills rather than just over-the-counter cream. The safest next step is a proper evaluation, especially if the rash is painful, spreading, or not getting better.

Sources

This article is for general informational purposes only and is not medical advice. Research findings can be early, limited, or subject to change as new evidence emerges. For personal guidance, diagnosis, or treatment, consult a licensed clinician. For current outbreak or public health guidance, follow your local health department, the CDC, or another relevant public health authority.