DCLS: It Looks Like Fungus…But Is It? A Deeper Look at Podiatric Dermatology, Nail Differential Diagnosis & Biopsy

In this episode of the Dean’s Chat Learning Series, Dr. Jeffrey Jensen and Dr. Johanna Richey welcome back Dr. William Scherer, Senior Podiatric Medical Advisor for Bako Diagnostics and a clinical consultant, for an engaging discussion on the importance of podiatric dermatology. Drawing from his experience in comprehensive podiatric practice, Dr. Scherer discusses why skin and nail disorders deserve the same diagnostic attention as musculoskeletal conditions. He emphasizes that podiatrists frequently encounter dermatologic pathology and have an opportunity to provide meaningful, sometimes same-day, treatment for patients.A major focus of the discussion is the evaluation of abnormal and dystrophic toenails. Dr. Scherer challenges clinicians to avoid automatically diagnosing onychomycosis based solely on appearance, noting that a significant percentage of dystrophic nails are not fungal infections. The conversation explores the role of laboratory testing in improving diagnostic accuracy and guiding individualized treatment. Dr. Scherer reviews the evolution of diagnostic methods, including KOH preparations, fungal cultures, PAS and GMS stains, Fontana-Masson staining, and PCR testing, explaining how each can contribute to the diagnostic process and when different tests may be most useful.The discussion also highlights the importance of maintaining a high index of suspicion for potentially serious pathology. The hosts and Dr. Scherer discuss concerning nail pigmentation and the evaluation of possible subungual melanoma, including clinical warning signs and the importance of appropriately sampling the nail matrix when malignancy is part of the differential diagnosis. The conversation reinforces a critical principle: removing the nail alone may not adequately sample the pathology responsible for a concerning lesion.Dr. Scherer also explores the relationship between biomechanics, repetitive microtrauma, onychodystrophy, and secondary infection, emphasizing that podiatrists' understanding of gait and mechanical forces provides a unique perspective when evaluating nail disease. The episode concludes with a broader message about comprehensive podiatric care: regardless of whether a patient presents with a complex surgical problem, sports injury, skin condition, or dystrophic toenail, the podiatrist's responsibility is to put the patient first, practice evidence-based medicine, maintain empathy, and strive for accurate diagnosis and appropriate treatment.