Doctors are prescribing antifungal creams at such high rates for patients with skin complaints that they may be contributing to the rise of drug-resistant infections, according to new research. These are “serious antimicrobial-resistant superficial fungal infections recently identified in the United States,” noted a team led by Jeremy Gold, a researcher at the US Centers for Disease Control and Prevention (CDC).
One of the biggest emerging threats is drug-resistant ringworm (a form of dermatophytosis). In Southeast Asia, there are major outbreaks of this itchy, circular rash that doesn’t respond to topical antifungal creams or pills. Cases of drug-resistant shingles have also now been reported in 11 US states, Gold’s team noted. This is “experiencing massive trauma to patients and delays in diagnosis,” the team said.
As seen with the overuse of antibiotics, fungi naturally develop resistance to antifungal drugs the more they are exposed to them. The CDC team believes that antifungal topical creams are being overprescribed.
Findings published in the latest issue of the CDC’s Morbidity and Mortality Weekly Report show that primary care doctors wrote the highest percentage of these prescriptions, but dermatologists and podiatrists had much higher rates on a prescription-per-doctor basis. One of the big problems, according to Gould’s team, is that most doctors diagnose skin conditions just by looking at it, a method that is “often wrong,” even among board-certified dermatologists. They added that “definitive diagnostic testing” of skin lesions beyond just looking at them is rarely done.
A small percentage of physicians are prescribing antifungal medications at extremely high rates. In 2021, “10 percent of antifungal prescribers are on almost half of these drugs,” the team found. The new study likely captures a fraction of the overuse of antifungals, since “most topical antifungals can be purchased over the counter without a prescription,” the researchers noted. High use of Clotrimazole-Betamethasone in particular is thought to be a major factor in the emergence of drug-resistant ringworm. This drug (a combination of a steroid and an antifungal) can also “cause skin damage when applied to genital areas,” meaning areas where the skin folds over itself, such as around the groin, buttocks, and armpits.
Long-term, extensive use of clotrimazole-betamethasone can also trigger hormonal problems, the team said. According to the researchers, the bottom line for suspected fungal skin infections is, “healthcare providers should be judicious in prescribing topical antifungals” and go beyond a visual diagnosis if possible.
Doctors should try to “educate patients about the proper use of topical antifungals and combination antifungal-corticosteroids” to help reduce the risk of overprescription and drug-resistant fungal infections, they added.