July 13, 2023

“The whole idea of antifungal resistance is relatively new; it just has come into our consciousness as providers in the last year or so,” said Warren Joseph, DPM, editor of the Journal of the American Podiatric Medical Association and presenter at this morning’s plenary lecture. Dr. Joseph will provide insight into this new reality, along with advice about how podiatric physicians can help the health-care system get ahead of antifungal resistance.

“Up to this point, we’ve always assumed there wasn’t resistance of dermatophytes to any of the antifungals we use,” Dr. Joseph said, pointing out that some classes of antifungals, such as the azoles, have been around for more than 50 years.

Nevertheless, international reports have emerged showing strains of dermatophytes that are resistant in particular to terbinafine. These resistant strains are quickly spreading worldwide.  

While antifungal resistance remains rare in the United States (in a recent study of 15,000 nail specimens, PCR testing showed only 4 percent of T.rubrum found carried the resistance gene), Dr. Joseph notes that podiatrists have one more potential factor to be aware of when a patient fails antifungal therapy.

“We have to practice good antifungal stewardship, just like we do with antibiotics,” Dr. Joseph said. “One of the ways to do that is to prove you are treating onychomycosis before you treat with an antifungal—50 percent of dystrophic nails are not fungal. If you start treating with an antifungal when you don’t have a fungus, it’s only going to drive resistance.”