A new "genital super fungus" is likely already spreading in the UK after several cases were reported in the US, experts have warned.

Trichophyton mentagrophytes type VII (TMVII) is an emerging dermatophyte fungus that may be spread during sex, according to the Centers for Disease Control and Prevention (CDC).

The new strain of ringworm can be highly inflammatory, causing painful, itchy, and persistent skin lesions on the genitals, buttocks, or face.

Ringworm, also known as tinea, is a common fungal infection that causes a rash that may be scaly, dry, swollen or itchy.

TMVII looks similar to typical ringworm, though it can be more inflamatory and harder to treat, with the pontential to cause abscesses and scarring if its not addressed.

According to the CDC, TMVII infections are usually not resistant to antimicrobials - i.e. medicines used to prevent and treat infectious diseases - but typically require treatment with oral medication, often for several months.

Dr David Denning, Infectious diseases expert at the University of Manchester, said it was "very likely that there are undetected cases" of the new strain in Britain, particularly cases in the early stages.

Speaking to MailOnline, he said: "Today if you had a rash on your chest or your back, you might not bother to deal with it for a week or two.

"If you were to go to a doctor and they prescribe something like a steroid or antibacterial cream but it doesn't work, we could be looking at six to eight weeks since it began.

"But you could have transmitted it in the first two or three weeks to a partner or a friend that you gave a big hug to, went swimming with. They would then get it and you'd start a cycle."

TMVII is likely no more transmissable then other skin fungi, but it is "very inflammatory meaning you get a much worse rash and usual treatments don't work", the academic said.

Dr Neil Stone, a specialist in infectious diseases, also said it was "inevitably" going to spread around the world, including in the UK.

TMVII has previously been found across Southeast Asia and Europe, with 13 cases recorded in France last year alone. 

The US's first known case was identified in New York City in June, a man in his 30s who reported having sex with a number of men during a trip to England, Greece and California.

Four more cases have been spotted since in the city, the CDC said in a report this week.

"All four patients were cisgender men aged 30-39 years who reported recent sexual contact with other men," the US's national public health agency said.

"Patients A and D reported sexual contact with each other, B and C had no known epidemiologic link to anyone with known TMVII infection.

"TMVII infections have been reported among men who have sex with men in France since 2021 and previously in men who have travelled to Southeast Asia for sex tourism."

The CDC says those who think they may have TMVII should avoid having sex.

The CDC warns: "Healthcare providers should be aware that TMVII can spread through sexual contact and cause lesions on the genitals, buttocks, face, trunk, or extremities.

"Patients should be advised about the importance of avoiding skin-to-skin contact with affected areas and not sharing personal items until symptom resolution."