Posted by an Infectious Diseases Resident:
A 48-year-old with diabetes and chronic renal failure was referred to a dermatologist for leg lesions that started as a solid, painless nodule, and grew after a suspected insect bite. Antibiotics had no impact on the lesions, and cutaneous leishmania was ruled out by a biopsy. A few dermatoligsts and an endocrinologist on Figure 1 diagnosed the patient with necrobiosi lipoidica, a rare condition that causes collagen degeneration. This feedback led to another biopsy, which confirmed the diagnosis.