First cases of drug-resistant ringworm (tinea) found in the U.S.A.

First cases of drug-resistant ringworm (tinea) found in the U.S.A.

The two recent New York City infections stemmed from a species of fungus named Trichophyton indotineae. Though infections caused by T. indotineae have been on the rise in South Asia during the last ten years – likely due to the overprescription and misuse of antifungal medications. These are believed to be the first reported cases in the U.S. It’s also spread throughout Asia and to Canada and Europe.

Contrary to what its name suggests, ringworm is not caused by worms, but by more than 40 different species of fungi. Symptoms include a ring-shaped rash, hair loss and itchy, red, scaly or cracked skin. The rash can form anywhere the fungus comes in contact with the body, but it commonly occurs on the feet, scalp, groin or beard areas.

These signs typically occur within four to 14 days of exposure. Historically, ringworm infections have been relatively mild and easy to treat with antifungal creams.

Trichophyton simii, shown here under a microscope, is one of 40 species of fungi that can cause ringworm infections.

Fungi tend to thrive in warm, moist conditions, so doctors should pay extra close attention to any drug-resistant ringworm infections as the temperatures start to heat up this summer, as Priya Soni, a paediatrician who specialises in infectious diseases at Cedars-Sinai Medical Centre said,

With globalization and just the travel that we’re going to see over the summer, this may be something that we may see more of as the months go on.”

One of the two U.S. cases was a 47-year-old woman who developed a bad rash while travelling in Bangladesh last summer. While there, she applied antifungal and steroid topical creams to the rash, but it didn’t get any better. When she returned to the United States, she went three separate times to an emergency room for relief from the ringworm. Again, doctors prescribed her several antifungal and steroid creams, but they did nothing to curb the rash.

Eventually, in December 2022, she visited dermatologists who tried a new strategy. They prescribed her a month-long course of oral antifungal medication known as Terbinafine. When her symptoms again failed to improve, they tried another antifungal medicine called Griseofulvin. Finally, most of the rash went away.

More information on these cases of drug-resistant ringworm
MyHSN has a related article 10 fungal infection facts