Exogenous Insulin Antibody Syndrome: An Overlooked Cause of Severe Hypoglycemia and Insulin Resistance in a Patient With Type 2 Diabetes Treated With Insulin

We report an 80‐year‐old man with type 2 diabetes who presented with life‐threatening hypoglycemia (36 mg/dL) and coma, requiring high‐dose insulin (74 units/day). Exogenous insulin antibody syndrome (EIAS) was suspected due to his glycemic instability and high insulin requirements. Subsequent testing confirmed elevated insulin antibodies (8.7 U/mL). Switching insulin analogues (to 32 units/day) promptly achieved stable glycemic control. This case highlights that EIAS, an under‐recognized cause of unpredictable glycemia in insulin‐treated diabetes, should be considered in patients with severe hypoglycemia and high insulin requirements. Modifying the insulin regimen is key for diagnosis and treatment.