Clues to Notice When Diagnosing Foot Infections in Dermatology Settings, with William Scherer, DPM, MS

During the 2025 SDPA Annual Summer Dermatology Conference in Washington, DC, William Scherer, DPM, MS, spoke in a session about strategies for clinicians to improve their ability to identify interdigital foot skin infections.

Scherer, known for his role as a Senior Podiatric Medical Advisor for Bako Diagnostics, spoke with the HCPLive team about foot web space infections, methicillin-resistant Staphylococcus aureus (MRSA), fungal versus bacterial infections, and more. In this segment of his interview, Scherer was asked about his talk’s portion on erythrasma and yeast infections, 2 underrecognized conditions that clinicians may require additional consideration to avoid missing.

“Well, the simplest thing is really old-school, especially with erythrasma, where you can use something known as a ‘Wood's lamp,’ Scherer said. “When you take the Wood’s lamp, and those maybe are $10, you can shine that on the foot, and if it fluoresces a coral red color, then that's pretty diagnostic for Corynebacterium or erythrosma. Again, taking a scraping and sending it off to the lab, doing PCR testing, is diagnostic. But the Wood's lamp is one of those old school tests, and I think almost every dermatologist in the country has a Wood's lamp.”

Despite the Wood’s lamp test’s longstanding use, Scherer noted that the test still stands the test of time. Scherer also discussed yeast infections.

“The yeast, a lot of times, will have a whitish color,” Scherer explained. “So sometimes in the interdigital space, you'll see something white, not too scary looking. A lot of times, that's your Candida or your yeast fungal infection. So one is bacteria that you can see with the Wood’s lamp. The other is going to be fungal, and for that you do visual identification and also a scraping, because a lot of times a yeast or a tenipedis or dermatophyte can clinically look very similar.”

Scherer was asked what he hopes clinicians, including physician associates viewing his talk at SDPA, will most remember from his session’s takeaways.

“The key thing is first and foremost, identification,” Scherer said. “A web space infection is relatively common during the summer months, is relatively common in younger patients, but in an older population, it can be a chronic condition. So it's really about increasing your awareness of the importance, [and knowing] that this is not just a simple fungal infection that you can treat with an over the counter product. A lot of patients try, and it fails, and they will come into your office.”

For more from Scherer and his session highlights, view the full segment posted above. To find out more about topics highlighted at SDPA, view the latest conference coverage.

The quotes used in this summary were edited for clarity.