A rare form of endogenous hypoglycemia uncovered after corticosteroid treatment.

Summary: We present the case of a 52-year-old Caucasian woman with insulin autoimmune syndrome (IAS) uncovered after corticosteroid treatment for lumbar pain due to disc herniation. We confirmed hypoglycemic episodes 4-5 h after food ingestion, associated with extremely high levels of insulin and the presence of anti-insulin antibodies, establishing the diagnosis of IAS. The most probable cause of the disease was glucocorticoid medication, considering she had no other autoimmune or hematologic disease associated. As the hypoglycemic episodes were mild, the patient received dietary recommendations (small, frequent, low-carbohydrate meals), and 3 months later, she had no more clinical episodes of hypoglycemia, with improved blood insulin level.

Learning Points: IAS is a very rare form of hypoglycemia in the Caucasian population, which is why critical thinking and active search are needed. Moreover, drug-induced cases of IAS in the Caucasian population are exceptional, with only one report of glucocorticoid medication as a trigger in the literature. Recognizing IAS is very important in order to avoid unnecessary investigations and choose the right treatment.