Health officials have made a discovery while treating a man who slept with multiple men.

They warned about a new case of ringworm likely spread through s3x, which has been reported in New York City, the first such case in the U.S.

Fox News reports that the infection, a rare fungus called trichophyton mentagrophytes type VII (TMVII), was detected in a man in his 30s, who reported having s3x with multiple men during a trip to England, Greece and California, according to a study published Wednesday at JAMA Dermatology by doctors at NYU Langone Health in New York City.

The report said the man developed a red, itchy rash on his penis, legs, and across his groin and buttocks when returned from his trip.

It also stated that the rash looks similar to eczema, a common condition that causes dry, itchy and inflamed skin, as opposed to the typical ringworm fungal skin infection that forms in circles.

Tests revealed he had the fungus and doctors prescribed him standard antifungal oral medications – but it took his body four and a half months to clear it.

The man took fluconazole for four weeks without improvement before moving on to terbinafine for six weeks and then itraconazole for eight weeks.

Doctors say he did not have any other infections that could have made the problem worse.

However, Dr. Avrom Caplan, an assistant professor of dermatology at the NYU Grossman School of Medicine and author of the new report, told NBC that there is no need for the public to be alarmed.

“There’s no evidence that this is widespread, or that this is something that people really need to be worried about,” Caplan told the outlet.

“But if people are having itchy eruptions in areas like the groin, and it’s not getting better, see a doctor,” he added.

John Zampella, who also co-authored the study, called on physicians to help identify the fungus.

“Since patients are often reluctant to discuss genital problems, physicians need to directly ask about rashes around the groin and buttocks, especially for those who are s3xually active, have recently traveled abroad, and report itchy areas elsewhere on the body,” Zampella said in the statement.

Fox News also reports that the man’s case is the first recorded in the U.S. and comes as doctors in France reported 13 such cases last year, according to a statement announcing the study.

Twelve of those patients were men who had s3x with men. The man said he had s3x with multiple male partners during his travels, none of whom reported similar skin issues.

Caplan said the infection was most likely transmitted through s3xual contact but he couldn’t rule out the possibility that he picked the fungus up at a sauna he had visited two months prior to his symptoms erupting, NBC reports.

According to the study, male genital fungi have been increasing in India, consistent with the emergence of a slightly different form of ringworm called trichophyton indotineae.

Climate, hygiene and bathing practices likely contribute to the spread of that fungus as well as s3xual contact.

Health experts warn that the infection causes similar itchy and contagious rashes as TMVII and poses a greater challenge for dermatologists since it often resists terbinafine treatment.