A Case of Type 1 Diabetes With Nocturnal Hypoglycemia After Desensitization Therapy for Insulin Allergy

Antibodies against exogenously injected insulin are common with insulin treatment but seldom have serious effects on blood glucose (1). In insulin autoimmune syndrome (IAS), however, the insulin antibody causes hypoglycemia (2) in the absence of exogenous insulin treatment.Here, we report a case of type 1 diabetes with insulin antibody, whereby the patient developed nocturnal hypoglycemia after desensitization therapy for an insulin allergy.After receiving insulin therapy for 1 year, a 61-year-old man was admitted to our hospital because of an insulin allergy and poor control of diabetes. He had an itchy eruption at the insulin injection site. At the time of admission, the patient presented with an HbA1c level of 16.2% (154 mmol/mol); anti-GAD antibody 80.0 U/L (<1.5 U/mL); serum C-peptide level 0.01 ng/mL after glucagon injection (fasting 0.67–2.48 ng/mL); and insulin-specific IgE 41.5 UA/mL (<0.34 …