A 65-year-old man with type 2 diabetes who presents to your office with 10 thickened, elongated, yellowed toenails (Figure 1). He reports that he first noticed the changes in his toenails about 3 months ago, at which time most of his nails were already involved. He was diagnosed with type 2 diabetes 4 years ago, and his blood sugar is currently poorly controlled on metformin alone. He has elevated triglyceride levels for which he is taking a low dose of simvastatin.
He is clinically obese, which may have contributed to the fact that he did not notice his toenail infection until it was well entrenched. On clinical examination, you observe that all of his toenails are yellow in color and 6 have white lateral streaks. Two nails show involvement extending proximally to the lunula. Several nails, including both great toenails, show subungual hyperkeratosis that is greater than 2 mm thick and…
