New York and federal health officials have issued a warning about two cases of a drug-resistant, highly contagious skin infection in New York City.
The new report, published late last week by the Centers for Disease Control and Prevention, linked two local cases of ringworm rash to an aggressive strain of a fungus named Trichophyton indotineae. This species is common in South Asia, and it’s a type of fungus known as a dermatophyte mold, meaning it needs protein in the skin to grow.
But one of the NYC cases could not be tied to overseas travel, suggesting the germ is spreading locally in the U.S. Despite being resistant to first-choice drugs, this fungal strain is still treatable with other medications.
Dr. Avrom Caplan, a dermatologist at NYU Langone Health, alerted public health officials in February of the two patients, whose conditions did not improve after receiving standard oral treatment. Both had severe cases of ringworm rash, which spreads easily through skin-to-skin contact. Caplan treated one of the patients at Langone and co-authored the CDC report.
He said the rashes on this patient were more inflamed than the average case of ringworm. Oral medications also failed to alleviate her symptoms.
"We've been alerted to this infection by our colleagues in India and elsewhere over the past number of years," Caplan said. "This particular patient had many of the features that they have been reporting."
Genomic sequencing a month later revealed both women had contracted an infection caused by the fungus Trichophyton indotineae independently of one another. The ringworm rashes caused by this species are often inflamed and itchy. They typically spread on the face, body, thighs and pubic area.
An example of a ringworm rash caused by a related fungus, Trichophyton rubrum.
The first of the two cases began in the summer of 2021, when a 28-year-old pregnant woman developed widespread rashes. After giving birth in January 2022 and being prescribed antifungal medication, her rashes persisted. She had had no recent international travel.
The second patient, a 47-year-old woman, first developed ringworm while visiting Bangladesh, where the strain is common. Once she returned to the U.S., doctors prescribed her four different treatments to no avail. Her husband and son have since reported similar rashes.
However, Caplan said community spread is "very hard to prove at this point" because of the small number of cases. He said, despite the CDC report, the threat level is low for most people, and that the warning is mostly a heads-up for doctors who encounter this rare condition. The report included pictures of what the two infections looked like.
"People should not be worried about this," he said. "The important takeaway points here are for clinicians in particular and for public health authorities. So, we know public health authorities are looking out for this, they've been looking out for it."
Despite the fungus's novelty in the U.S., health officials have previously reported cases throughout Asia, Europe, and Canada, according to the CDC. The agency linked the rise of the strain to the "inappropriate use" of common topical steroids used to treat the infection.
Both women identified in the CDC report recovered from their rashes after receiving extended therapies.
The biggest threat regarding the rashes is chronic relapse, which, Caplan said, is common among patients in other countries.
Though Caplan stressed that the average person should not be on high alert when it comes to Trichophyton indotineae, he said those with reason to believe they're infected should immediately "seek advice from a clinician instead of using over-the-counter creams or medications obtained through friends and loved ones.
Officials from the New York City Department of Health did not immediately respond to a request for comment.
