Generalised allergic reaction to human insulin

Solitary pancreas transplantation for life-threatening allergy to human insulin*

We report on a 30-year-old man, with type 1 diabetes mellitus, who developed generalized allergy to insulin consisting of several bouts of tremor, tachycardia, breathlessness and syncope. Strong positive reactions to protamine and metacresol were demonstrated by skin-prick testing. Symptoms persisted despite the use of antihistamine therapy, Actrapid HM Paraben and Monotard (insulin without protamine and metacresol) and immunosuppression (tacrolimus). He underwent a cadaver pancreas transplantation with portal-enteric drainage in June 2003. Following the antithymocyte globulin induction, immunosuppression consisted in tacrolimus and sirolimus without steroids. The patient subsequently reported a complete resolution of his symptoms and excellent glycaemic control. Thirteen months after transplantation, the patient developed oral ulcerations and severe leucopoenia initially attributed to sirolimus, which was subsequently stopped. A hyperglycaemic episode following corticosteroid therapy for acute rejection therapy required the reintroduction of insulin. Allergic manifestations reappeared promptly. Currently, 2 years after transplantation, the patient is euglycaemic without insulin (glycated haemoglobin 5.8%) and he is free of allergic reactions.

A rational clinical approach to suspected insulin allergy: status after five years and 22 cases

AIMS

Allergy to recombinant human (rDNA) insulin preparations is a rare complication of insulin therapy. However, insulin preparations contain several allergens, and several disorders can resemble insulin allergy. Studies evaluating the diagnostic procedures on suspected insulin allergy are extremely few.

METHODS

Since January 1998, we have used a standardized investigative procedure during admittance to the medical ward allowing observation and repeated recording of reactions to intradermal skin test (performed with a commercially available kit containing isolated insulin allergens). Data on all investigated cases until April 2003 were collected retrospectively, and self-reported efficacy of intervention was compared to clinical data.

RESULTS

Twenty-two patients were included. In nine (41%) cases, non-insulin allergic causes were discovered and successfully treated: poor injection technique (n = 5), skin disease (n = 3) and other systemic allergy (n = 1). Nine other patients were found to be allergic to protamine (n = 3) or rDNA insulin (n = 6), and specific treatment was associated with relief in 8 patients (89%). Four patients had local reactions of unknown causes but symptom relief was obtained in three cases by unspecific therapy. Overall, 20 (91%) reported relief of symptoms.

CONCLUSION

Our standardized investigative procedure of suspected insulin preparation (IP) allergy was associated with relief of symptoms in > 90% of patients. IP allergy was diagnosed in 41%, and intradermal testing with isolated insulin allergens was a prerequisite in identification of culprit allergen and targeting of treatment.