Use of Inhaled Insulin in a Patient with Subcutaneous Insulin Resistance Syndrome: A Rare Condition

ABSTRACT Objective: Subcutaneous insulin resistance syndrome (SIRS) is a rare entity, characterized by increased resistance to subcutaneous insulin and normal sensitivity to intravenous insulin, with no increase in circulating insulin antibodies. Little is known about its pathophysiology, but it has been suggested to occur due to rapid subcutaneous degradation of insulin. Multiple treatment modalities have been used in the past to treat this condition. Methods: We illustrate a case of a 17-year-old girl with type 1 diabetes mellitus (T1DM), presenting with recurrent episodes of diabetic ketoacidosis (DKA) due to resistance to subcutaneously delivered insulin. Results: We describe the challenges faced while attempting different modalities during her hospital stay, and eventually using inhaled insulin, which was recently approved by the Food and Drug Administration for use in nonpregnant adults with T1DM. Conclusion: SIRS is a difficult condition that may lead to patient frustration and carries a serious risk of recurrent DKA. We described this case to create awareness about SIRS, provide insight into the challenges of its management, and report the use of inhaled insulin to successfully dose meal-time insulin, along with intramuscular glargine for basal insulin. Abbreviations: BG = blood glucose DKA = diabetic ketoacidosis IM = intramuscular IV = intravenous SIRS = subcutaneous insulin resistance syndrome TDD = total daily dose U = units