Excessive use of antifungal creams leads to an increase in drug-resistant fungal skin infections
According to a report by the US Centers for Disease Control and Prevention , antifungal creams and the combination of antifungal drugs with corticosteroids are likely to cause an increase in the prevalence of acute fungal infections of the skin, scalp, and nails.
In 2023, dermatologists in the US reported for the first time highly contagious, drug-resistant fungal skin infections that did not respond to our available antifungal drugs.
These drug-resistant fungal infections first appeared in Southeast Asia, then spread to China and beyond, and are now reported in 11 US states.
To find out, researchers from the US Centers for Disease Control and Prevention (CDC) studied the prescribing of antifungal drugs by doctors in the US throughout the year to determine which types of clinicians prescribed which drugs to patients.
As with the rise of antibiotic resistance among bacteria, the overuse of antifungals allows potentially pathogenic fungi to find ways to escape drugs, especially when they are misprescribed or misused for other types of infection.
By looking at antifungal prescribing practices, CDC epidemiologist Kathleen Benedict and her colleagues hoped to gain important insights that could help address the problem before it gets worse.
"The high prescribing of topical antifungal agents in the context of the emergence of resistance highlights the need to better understand current prescribing practices and encourage judicious prescribing by physicians, as well as to improve patient education about recommended use," the researchers wrote.
The researchers looked at data from about a million professionals who in 2021 prescribed drugs to nearly 49 million patients under Medicare, the US government's national health insurance program.
It found that in 2021, approximately 6.5 million prescriptions for topical antifungal drugs were dispensed in the US, with a total value of $231 million.
"The actual use of topical antifungal drugs should be higher than the study found, because the majority of these drugs are purchased by people without a prescription," the researchers wrote.
In 2021, the majority (40 percent) of antifungal medications were prescribed by primary care physicians, followed by dermatologists and podiatrists.
While all of this points to potential overuse or at least liberal prescribing practices, the Medicare data does not include diagnostic information about what type of fungus patients had. Therefore, researchers cannot determine whether a patient was prescribed the appropriate medication to treat a particular disease, or whether doctors checked for infection first to know which medication to prescribe.
Benedict and his colleagues were alarmed by the high prescribing of clotrimazole-betamethasone, which accounted for 15 percent of topical antifungal prescriptions. It is believed that this combination of drugs is a potential cause of the appearance of drug-resistant fungal skin disease - tinea , also known as dermatophytosis.
The researchers also note that doctors often diagnose skin diseases simply by looking at the skin, which often leads to misdiagnosis.
The study was published in the Morbidity and Mortality Weekly Report .
Prepared by ScienceAlert.