Novel fungal skin infection in U.S. prompts vigilance from dermatologists

Key takeaways:

• The fungal skin infection is caused by T. mentagrophytes type VII, a dermatophyte.
• The infection is found mostly in the genitalia of men who have sex with men.

Dermatologists should be on the lookout for new forms of a highly contagious fungal infection now being reported in the U.S., according to a press release from NYU Langone Health.

In one of two studies published in JAMA Dermatology, researchers from NYU Langone Health documented the first reported case of a sexually transmitted fungal infection presenting as a rare manifestation of dermatophytosis in the U.S.

According to Avrom S. Caplan, MD, assistant professor in the Ronald O. Perelman department of dermatology at NYU Grossman School of Medicine and the study’s lead author, the fungal skin manifestation is caused by Trichophyton mentagrophytes type VII which has been referred to in the literature as TMVII. It is a dermatophyte, which is a type of fungus that causes ringworm, jock itch, athlete’s foot or tinea capitis. However, this dermatophyte presents itself differently than most forms.

Avrom S. Caplan

“What’s different about this particular dermatophyte is the involvement of the genital region,” Caplan told Healio. “This is something you don’t typically see in a dermatophyte infection.”

According to the report of the first case published in JAMA Dermatology, a man in his 30s from New York City developed tinea on his penis, buttocks and limbs after having sex with multiple male partners during his travels throughout Europe. While none of the other men reported similar skin issues, this sexually transmitted form of ringworm has been increasingly diagnosed throughout Europe primarily in men that have sex with men.

“The data are very limited of this particular infection,” Caplan explained, “but in some of the reports of this impacted patient population, we are seeing lesions that are a little bit less typical than the common dermatophyte or ringworm infection.”

According to the reports, the tinea presented in these patients do not resemble most forms of ringworm but can instead be confused for eczema, causing patients to undergo the wrong type of treatment. Caplan also explained that reports in the literature in France claim the tinea could be inflammatory and could cause abscesses which may lead to infection and scarring.

While a second study led by NYU researchers and published in JAMA Dermatology found presentations of a similar fungal strain, Trichophyton indotineae, that resists standard therapies, Caplan stated that TMVII is treatable.

“There have been a couple of cases where people have changed antifungal therapies, but the data we still have at this point suggest it responds to oral terbinafine,” he said.

With this being the first confirmed case of TMVII reaching the U.S., Caplan emphasized that this infection is currently “not an endemic and it is not rapidly spreading,” but clinicians should be on the alert for signs and symptoms of the condition.

“The reason we put the report out there is to highlight primarily for clinicians to think about dermatophyte if you’re seeing this infection,” he said. “Especially if the patient has painful lesions or scaly rashes involving the genitalia, consider this atypical form of ringworm rather than just psoriasis and eczema.”

References:

• Caplan AS, et al. JAMA Dermatol. 2024;doi:10.1001/jamadermatol.2024.1430.
• Caplan AS, et al. JAMA Dermatol. 2024;doi:10.1001/jamadermatol.2024.1126.