Do diabetic foot ulcers often have antifungal resistance?

Diabetic foot ulcers (DFUs) are serious wounds that can become infected with fungi, most commonly Candida species. Antifungal resistance means the drugs used to treat these infections stop working well. Research shows that resistance is a real concern in DFUs, but the level of resistance depends on the specific antifungal drug and the type of Candida. This is important because untreated or resistant fungal infections can slow healing and raise the risk of amputation.

What the research says

A 2024 systematic review and meta-analysis found that antifungal resistance in Candida species from DFUs is high ³. The highest resistance was to nystatin (32.48%), itraconazole (19.46%), and fluconazole (16.4%). The lowest resistance was to miconazole (1.18%) and caspofungin (4.69%) ³. Resistance was higher in Candida albicans than in non-albicans species ³. A study from Kenya reported that 26% of Candida albicans isolates from DFU patients were resistant to fluconazole, and 11% were resistant to caspofungin ¹¹. Another review noted that fungi are detected in about 31% of DFUs by sensitive testing (PCR), but only 9% by standard culture, meaning fungal infections may be underdiagnosed ⁹. The same review highlighted that multidrug resistance in bacterial isolates from DFUs exceeds 90% in some studies, and mixed bacterial-fungal infections are common and linked to worse outcomes ⁹¹⁰. Antifungal resistance is a growing problem, and new treatments like antimicrobial peptides are being explored ¹⁰.

What to ask your doctor

• Should my diabetic foot ulcer be tested for fungal infection, and if so, which test is most accurate?
• If a fungus is found, how will you determine which antifungal drug will work best?
• Are there any signs that my ulcer might have a resistant fungal infection?
• Could a mixed bacterial and fungal infection be affecting my healing?
• What are the options if the first antifungal treatment doesn't work?