Type I allergy to insulin: case report and review of localized and systemic reactions to insulin.

Allergic reactions to insulin preparations are not uncommon. Although patients often present with skin symptoms, most articles on insulin allergy are published in endocrinology and allergy journals. The purpose of this report is to describe a case of localized type I allergy to insulin as well as provide a review of the classification of insulin allergy, methods of evaluation, and management options.