SUN-693 What Else Should Be Done in Patients with Uncontrolled Type 2 Diabetes and Severe Insulin Allergy?

Introduction: Insulin allergy in patients with diabetes mellitus is a very rare condition. The immediate vital implications for the patient call for prompt diagnosis and management of insulin allergy. We present a case of a patient that was unable to tolerate the insulin desensitization process, however; he was successfully treated with antidiabetics’ medications following the AACE guidelines for the management of type 2 diabetes (T2DM).Case description:31 years old obese Caucasian male with a BMI of 35, a history of T2DM and insulin allergy who was admitted to the hospital with hyperglycemia and osteomyelitis of the right foot. Endocrinology was consulted for the management of diabetes. Laboratory results showed hemoglobin A1C 11.1%, C peptide level 2.79 with blood glucose 283 mg/dl with negative insulin specific IgG level and elevated Ig E levels. The patient was actually diagnosed with T2DM in 2001, then started on metformin, glyburide initially. Given uncontrolled diabetes he was started on insulin in 2007 however, he developed an allergic reaction to different types of insulin (including anaphylactic reaction) so he was referred to allergy and immunology for further testing and possible desensitization. He had an allergy to human, bovine and porcine insulin. Exclusion of other causes of allergy including latex, protamine, and zinc was performed by the immunologist. Trial of insulin desensitization (using NPH and regular Insulin) failed. He also developed an allergic reaction to different medications including sulfonylurea, SGLT2 inhibitors, DDP4 inhibitors, and alpha-glucosidase inhibitors. During the inpatient setting in 2019, we assessed the patient and considered different options available; bromocriptine versus amylin products versus fish insulin versus IGF1 (as of last resort). Other options were another desensitization process in the ICU setting with transitioning to an insulin pump, however, the patient refused that option. We started the patient on bromocriptine mesylate(cyclocet) with pioglitazone and the A1C improved in the next 3 months from 11.1%-->9.8%. The patient is still following up with us and plans for desensitization once the osteomyelitis of the foot is controlled. Discussion and conclusion: Insulin allergy is a rare but severe condition that calls for immediate work-up. It can be managed well in close cooperation between the endocrinologist and the immunologist. Our patient developed IgE-mediated symptoms occurring immediately after insulin injection and confirmed by intradermal skin testing. Specific immunotherapy has been reported in case reports in the literature and should be considered for these patients Following AACE guidelines for the management of T2DM with the addition of bromocriptine mesylate until desensitization was a beneficial option for our patient.