Allergy to human insulin or its analogs is rare, but it is still a significant issue in current diabetes care. Allergic reactions can range from localized injection site reactions to generalized anaphylaxis, and they can be caused by excipients or the insulin molecules themselves. We presented a case of a 14-year-old male patient with generalized allergic reactions to insulin glargine and insulin detemir. The patient was successfully managed by being switched to a continuous subcutaneous insulin infusion with insulin aspart. Allergic reactions to insulin detemir and insulin glargine have both been well described, with insulin detemir allergy appearing to be more common. There are several potential mechanisms for insulin allergy, and immunologic characteristics vary among different insulin analogs. After confirming insulin allergy in practice, management involves treating symptoms and switching insulin preparations. This is the first documented case of allergies to both insulin glargine and insulin detemir in a pediatric patient. Exact mechanism of insulin allergy is unknown, and management strategies must be individualized for each patient.