From Skin Deep to Life-Threatening: A Case of Necrotizing Fasciitis Masquerading as Ecchymosis.

Necrotizing fasciitis (NF) is a rare but life-threatening infection characterized by rapid and extensive tissue necrosis. Early identification is often difficult, particularly when physical exam findings are subtle or atypical. We present the case of a man in his forties with poorly controlled type 2 diabetes mellitus who arrived at the emergency department after noticing discoloration and swelling of his right great toe. The patient had minimal pain but was noted to be hypotensive and tachycardic on arrival. Laboratory workup revealed hyperglycemia, hyponatremia, and elevated lactic acid. Imaging was negative for fracture or subcutaneous air. Due to the rapid progression of symptoms and abnormal vital signs, general surgery was consulted to evaluate for NF. The patient was admitted and subsequently developed a temperature of 106°F, requiring escalation of care. He underwent surgical debridement and amputation of the right hallux. Wound and blood cultures grew Staphylococcus aureus, and he was later diagnosed with Staphylococcus-associated glomerulonephritis, confirmed by renal biopsy. This case demonstrates the importance of early recognition and intervention in NF, particularly in patients with diabetic neuropathy, and highlights a rare complication of S. aureus infection.