Intractable Hypoglycemia in the Setting of Autoimmune Overlap Syndrome

Evaluation of hypoglycemia in a patient with known diabetes mellitus, although usually straightforward, can at times be challenging. We present the case of an 8 year-old Latina girl initially diagnosed with type 1 diabetes mellitus in the setting of multiple autoimmune disorders, including dermatomyositis and lupus nephritis. She subsequently developed signs of insulin resistance and severe hypoglycemia, which was found to be due to insulin-receptor autoantibodies. This condition, known as type B insulin resistance, is a rare, heterogeneous metabolic disease that may feature hypoglycemia in the setting of extreme insulin resistance and hyperinsulinemia and, in this case, masqueraded as type 1 diabetes mellitus. The presence of hypoglycemia in the setting of multiple autoimmune disorders should prompt consideration of autoimmune-mediated hypoglycemia. In addition to immunologic modifying therapies, advances in diabetes care in the form of continuous glucose monitoring have provided an additional tool to manage recurrent hypoglycemia.