2 cases of drug-resistant ringworm detected in New York City, CDC report finds
The first U.S. cases of a drug-resistant strain of ringworm have been detected in New York City, according to a report from the Centers for Disease Control and Prevention.
Ringworm, also called tinea, is a skin infection caused by a fungus (not a worm) that can cause an itchy, red rash on many areas of the body. For example, what's commonly referred to as "athlete's foot" is actually a type of ringworm infection, the American Academy of Dermatology explains.
Typically, ringworm infections are treated with antifungal creams or oral medications. But the two NYC patients didn't respond to the usual treatments, signaling the arrival of a drug-resistant strain of fungus that hasn't previously been recorded in the U.S.
Two patients with drug-resistant ringworm
The first patient noticed her symptoms while in Bangladesh in the summer of 2022. While there, the 47-year-old woman used multiple steroid and antifungal creams and noted that her family members developed similar rashes.
Once back in the United States in the fall, she ended up visiting the emergency department three times to alleviate the rashes on her thighs and buttocks, resulting in prescriptions for more steroid and antifungal creams. Her symptoms didn't get better after taking the antifungal medication terbinafine in topical or oral forms.
After four weeks on griseofulvin, yet another antifungal medication, she had about an 80% improvement, according to the report, and dermatologists are now considering whether to give her itraconazole, another antifungal. Meanwhile, her husband and son are undergoing evaluations for their symptoms.
Her rash looked “pretty classic for tinea, but it was sort of all over her body and it was very itchy,” Dr. Avrom Caplan, an assistant professor of dermatology at the NYU Grossman School of Medicine and one of the authors on the CDC report, tells TODAY.com
And when he heard that she’d been traveling and that the rash had spread to her family members, “my radar goes up,” Caplan recalls.
After treating this patient, Caplan connected with colleagues who'd treated a similar case previously. "Sure enough, there was another patient who had failed first-line therapy, which is pretty classic for this type of infection," he says.
This patient, a 28-year-old woman, developed widespread rashes in the summer of 2021.
In December of that year, she was in her third trimester of pregnancy and the rashes were most pronounced on her neck, stomach, pubic area and buttocks. At that point, dermatologists diagnosed her with ringworm and prescribed her terbinafine in January 2022 after she gave birth.
However, after two weeks, her rash hadn’t improved. So, she was put on itraconazole, another antifungal drug, for four weeks. And that finally did the trick, although she’s still being monitored in case her symptoms return, the report says.
Further testing of samples from both patients revealed they had a particular strain of tinea infection. While this strain, Trichophyton indotineae, is so common in India that it’s reached “epidemic proportions,” the CDC says, there have only been scattered cases reported in Europe and Canada.
And, Caplan says, these two appear to be the first cases officially documented in the U.S., which has dermatologists concerned.
"Terbinafine is a medicine that has been FDA-approved for treatment of fungal infections for many, many, many years and it's very effective," Dr. Shari Lipner, associate professor of clinical dermatology at Weill Cornell Medicine, tells TODAY.com.
"A lot of times it's our go-to treatment for fungus," she explains. "So if there are strains that are becoming resistant to this drug, we have a problem."
That said, for the public, “it is reassuring that we don’t just have one oral antifungal — we have several options available,” Dr. Melissa Levoska, an assistant professor of dermatology at the Icahn School of Medicine at Mount Sinai, tells TODAY.com.
And while this is something the expert community should definitely be aware of, “I don’t think it should raise alarm as much for the general population,” she says.
Ringworm infection symptoms
A ringworm infection can affect pretty much any part of your body where there's skin, including your scalp, face and trunk, Lipner says. And it can also affect the nails.
Generally, a ringworm infection presents as an itchy circular red rash with scaly skin, Lipner explains. But the exact symptoms you might experience depend on where the rash is.
These are the most common symptoms of ringworm infections, according to the CDC:
A ring-shaped rash.
Itchy skin.
Cracked, scaly skin.
Skin redness.
Hair loss.
If you have a rash that you think might be tinea and it isn't getting better, skip the over-the-counter creams and go straight to your doctor or dermatologist, Levoska says.
"When patients are using over-the-counter topical steroids or topical steroids that they have for another condition, that can sometimes mask the infection," she explains. "So it can make it harder to diagnose."
The other problem with using over-the-counter antifungal products is that they can contribute to antifungal resistance, Lipner says. "People have eczema and they think it's a fungus and they're treating it with an antifungal," she says, "and that eventually causes resistance."
Taking an incomplete course of prescription antifungal medication or using prescription antifungals to treat other types of infections also fuels resistance, she says.
Ringworm infection treatments
The way a doctor treats ringworm depends on the symptoms and the specific type of infection. Generally, antifungal creams, sprays or powders are the first options, and that can include over-the-counter products depending on the body part you're treating, the AAD says. For severe ringworm infections or infections in certain areas of the body, a prescription treatment like terbinafine may be necessary.
Unfortunately, those first-line treatments don't always work to treat drug-resistant infections. And alternative medications need to be used for a longer period of time.
“Typically with run-of-the-mill ringworm, I give them an antifungal cream they use it for two weeks or four weeks and they’re better,” Caplan says. “Now you’re giving people oral medicines for 12 weeks... And even then there can be a relapse.”
Not only does that mean more time with itchy rashes, but these medications can also come with more side effects and potentially interfere with other drugs a patient might be taking, Lipner notes. For instance, "in older people who are taking hypertension medicines and statins for their cholesterol, it's difficult to give these alternative antifungal drugs," she says.
Drug-resistant cases on the rise
Several elements of these cases are troubling, the study authors write. For starters, one patient hadn't traveled outside the U.S.
In that case, "We really couldn't uncover an epidemiologic link to other people who have this or to traveling, so it suggests the possibility of local spread," Caplan says. "And because of how hard it is to test for this, it's certainly possible that there were some cases here before we confirm these."
But both possibilities are tough to prove, he adds.
There are tests that allow doctors to know which strain is causing a particular infection and which drugs will work to treat the infection. But that type of testing isn't as widely used as it should be, Lipner says. "We're trying to spread the word that physicians can send testing for rerbinafine resistance," she says, "and this may affect how we treat people."
Doctors also aren't required to report cases of drug-resistant ringworm infections to public health authorities, the CDC says, so it's hard to know exactly how common these infections are.
Caplan expects to see more cases. He's already confirmed a third case in his practice and says his team and the CDC are investigating "a handful" of other possible cases now. He hopes that the new report will raise awareness among dermatologists and encourage them to keep a lookout for more.
And for experts, this is yet another example of drug resistance simply becoming more common. And it underlines the need to stay ahead of the curve on monitoring these infections and developing new potential therapies.
"We have bacteria that are becoming resistant to antibiotics and now fungal infections are becoming resistant to antifungals," Levoska says. "It's just the status quo. And it's going to keep happening, (which is why) need to keep doing the research to keep up with these changes."
This article was originally published on TODAY.com
