[Systemic and local allergy to human insulin]

After introduction of recombinant human insulin, immunological reactions have become rare, but symptomatic immune reactions to insulin still occur. We present four insulin-treated diabetic patients who developed hypersensitivity to insulin or additives to insulin preparations. We show that symptomatic immunological reactions to insulin have not been eliminated by the introduction of recombinant human insulin. Furthermore it demonstrates the importance of skin-biopsy-verified diagnoses and the relevance of differentiation between different types of insulin allergy.