Occult Necrotizing Fasciitis Presenting as a Severe Hyperosmolar Hyperglycemic State in a Patient With Newly Diagnosed Type 2 Diabetes Mellitus.

Necrotizing fasciitis is a rapidly progressive and life-threatening soft tissue infection in which early diagnosis remains challenging when initial clinical findings are subtle or nonspecific. Hyperglycemic crises are frequently triggered by infection and may obscure the underlying etiology when metabolic abnormalities dominate the initial presentation. We report a case of a 52-year-old female with rheumatoid arthritis receiving chronic corticosteroid therapy, an important risk factor for atypical infectious presentations, who presented with altered mental status, dehydration, and severe hyperglycemia consistent with hyperosmolar hyperglycemic state in the setting of newly diagnosed type 2 diabetes mellitus. Initial evaluation revealed no clear infectious source aside from mild localized edema, and the patient was treated with intravenous fluids, insulin infusion, and broad-spectrum antibiotics. Despite early biochemical improvement, she developed persistent hyperlactatemia, refractory hypotension, and progressive lower extremity swelling with subsequent crepitus. Imaging revealed extensive gas within the deep fascial planes consistent with necrotizing fasciitis, requiring emergent surgical intervention. The patient improved following definitive management and was ultimately discharged. This case highlights the importance of continuous clinical reassessment and maintaining a high index of suspicion for occult infections in patients with hyperglycemic crises who fail to improve as expected.