What Is a Fungal STD? Understanding the Emerging TMVII Ringworm Strain

A sexually transmitted infection (STI) is an infection passed from one person to another through sexual contact. According to the most recent estimates, roughly 20% of adults in the U.S. have an STI at any given time. Chlamydia, trichomoniasis, genital herpes, and human papillomavirus (HPV) collectively account for about 98% of existing STI cases and 93% of new cases.

Trichophyton mentagrophytes genotype VII, or TMVII for short, is an emerging and highly contagious fungal infection. Since TMVII exclusively spreads through skin-to-skin contact, including vaginal, anal, and oral sex, it is considered the first known sexually transmitted fungal infection. We’ll discuss what researchers have learned about TMVII so far, and how this STI differs from other types of fungal infections like jock itch, ringworm, and yeast infections. 

Could a Fungal Infection Actually Be an STD?

Vaginal yeast infections, jock itch, and other fungal infections can be transmitted through skin-to-skin contact between partners, including sex. However, these conditions are not strictly considered STIs because they can also occur due to hormonal imbalances, side effects from new medications, and other internal body changes. In other words, sex can lead to yeast infections and jock itch under certain conditions, but a person does not need skin-to-skin contact to get these infections. 

TMVII, on the other hand, is strictly a fungal infection STI because it spreads exclusively through skin-to-skin contact and primarily through sexual activity. In the next section, we’ll go over the defining characteristics of TMVII and why it’s such a major concern among medical experts.

What Is the New TMVII Ringworm Strain?

TMVII is a relatively new strain of tinea, or ringworm, that produces a noticeable rash when someone is infected. While researchers have known about TMVII since the early 2010s, the first case in the U.S. was officially confirmed in 2024. 

Transmission of TMVII can easily occur when the rash of one person touches the uninfected skin of another person. Unlike standard ringworm, which can transfer from person to person through various types of skin-to-skin contact, TMVII appears to primarily spread during sexual activity. TMVII can also transfer between partners who share personal items such as bath towels, bedding, clothing, razors, and sex toys.

TMVII is a cause for concern among medical experts because it is highly contagious and produces more severe symptoms than other fungal skin infections. 

TMVII Symptoms

The telltale symptom of TMVII is a rash characterized by the following characteristics:

• Appearance: The rash usually appears as ring-shaped red, pink, or purple lesions with a slightly raised edge. Lesions are darker or discolored compared to the surrounding skin. Bumps and pustules may also appear around hair follicles in the affected areas.
• Distribution: The rash most commonly appears on the penis or vulva (genitalia), buttocks, anus, and face.
• Feeling: The rash is typically itchy and painful, with possible blistering and scaling. Unlike standard ringworm, TMVII lesions are prone to severe inflammation. 

Since TMVII is a relatively new infection, doctors routinely mistake its lesions for symptoms of other conditions such as eczema, psoriasis, or standard ringworm. However, TMVII does not normally respond to over-the-counter topical medications and requires a more robust treatment course.

Fungal Infection or Fungal STI?

TMVII’s symptoms can resemble the symptoms of non-STI fungal infections, making it harder to diagnose and treat. The table below lists basic differences between TMVII and other common fungal infections.

Fungal STI Treatment: TMVII Prevention and Treatment

Current medical guidelines advise people with TMVII to avoid any skin-to-skin contact with their partner, including intimate and sexual activity. Barrier methods for preventing STIs, such as using a condom, may help reduce the risk of transmitting TMVII. However, the rash can still spread to areas of skin outside the condom, so barrier methods are not completely effective. 

Once someone has tested positive for TMVII, doctors typically prescribe antifungal medication. The standard treatment for TMVII is a daily 250mg dose of oral terbinafine (Lamisil) for up to 12 weeks, though many people complete their treatment course in 6 to 8 weeks. Providers normally instruct patients to continue treatment for up to 2 weeks after the symptoms have resolved to ensure the infection is gone and to prevent recurrence.

Over-the-counter anti-itch and topical steroid creams are ineffective against TMVII and other severe fungal infections. These medications primarily work on localized areas of the outer skin, and are not strong enough to penetrate the blood-brain barrier and support the systemic changes needed to eradicate TMVII. Over-the-counter topicals can even mask TMVII’s skin-level symptoms and make the infection harder to diagnose.

Your Next Steps

If you suspect you have a TMVII infection, contact your medical provider. Skin scrapings and fungal cultures collected during your appointment are used to determine whether you have TMVII or another type of infection. After receiving a diagnosis, it is essential for you to follow all treatment protocols and complete the treatment course as instructed. Otherwise, the infection may not fully heal.

If you are diagnosed with TMVII, inform any current sexual partners so they can contact their doctor if they notice any new or unusual rashes. Cover all visible lesions with a bandage or cloth to prevent accidental skin-to-skin transmission while it heals. If you live with someone, immediately stop sharing linens, clothing, and other personal items until treatment has concluded and the infection has completely resolved.