ABSTRACT
Allergic reaction to insulin is mediated by several mechanisms; differences in amino acid sequence of animal and human insulin, altered tertiary structure of insulin and the presence of non-insulin protein contaminants or pharmaceutical additives. Anaphylactic reactions to insulin only occur in 0.1 to 2% of patients who stopped insulin therapy and have then resumed treatment. We report a diabetic patient who suffered severe anaphylactic reactions to human recombinant insulin, successfully treated by desensitization. A 19-year-old man with type 1 diabetes receiving Insulatard HM(R) developed generalized urticaria and angioedema with progression to dyspnea, dizziness and syncope. Skin prick test to all kinds of human recombinant insulin products revealed immediate type hypersensitivity and the titer of insulin IgE was increased in serum. The desensitization trial with Velosulin HM(R) using modified desensitization method was performed. Six months after the desensitization he was taking Velosulin HM(R) as well as Insulatard HM(R) without any evidence of systemic allergic reactions.