Management strategies for patients with insulin allergy at risk of acute complications: experience from a case report

Insulin allergy is a difficult challenge in treating patients with poor control of type 2 diabetes mellitus (T2DM), who are at risk for developing diabetic ketoacidosis (DKA) and hyperglycemic hyperosmolar syndrome (HHS). Currently, there are no established guidelines that provide standardized treatment protocols for this issue. We report the case of a 50-year-old man with T2DM and poorly controlled blood glucose who required insulin therapy but was allergic to insulin. This allergic reaction involved a progressive and severe rash and itch that occurred at the injection site and on the patient’s chest and back. After successful desensitization and 3 months of follow-up, we summarize the treatment protocol for insulin allergy in high-risk patients. We used a regimen of continuous subcutaneous insulin infusion (CSII) with Basal Insulin Desensitization, including CSII with rapid-acting insulin and the intradermal injection of long-acting insulin for simultaneous desensitization. After successful desensitization and 3 months of follow-up, the patient achieved stable glycemic control (HbA1c: 7.2%, fasting blood glucose: 6.5 mmol/L, postprandial glucose: 8.1 mmol/L) with no recurrence of allergic reactions. We summarize the treatment protocol for insulin allergy in high-risk patients.