Hypersensitivity to insulin

Great progress The use of purified insulins obtained by genetics has dramatically lowered the frequency of insulin hypersensitivity. This frequency has decreased from 1 to 55% with non purified insulins and to 0.1 to 2% with newly generated insulins. Diagnostic measures The anamnesis should clarify the allergic background of the patient, previous treatments with insulin, their duration of use and any eventual reactions. Examination of the lesions must assess the type (papule, eczema, purpura), the localization and extent. The second step skin tests, when negative, eliminate the responsibility of the insulin tested. They also participate in the search for cross-reactions between the various insulines. Their positivity is not always synonymous of hypersensitivity. Strategy to be applied in the case of localised cutaneous reactions, spontaneous regression is generally observed, the association of an oral antihistamine and/or the fractioning of the dose and its injection on several different sites often leads to the disappearance of these reactions. If the reactions persist, topical or oral corticosteroids of short duration can be useful. Finally, the switch to another insulin or even a tolerance induction with the least skin test reactive insulin as a last resource. The most severe systemic reactions are an indication for tolerance induction. (C) 2004, Masson, Paris.