[Patterns of allergic skin reactions during insulin treatment (author's transl)].

Intracutaneous testing was done in 85 patients with allergic reactions during insulin treatment. Six patients showed immediate reactions (type I), 76 showed allergic late reactions (type IV) and three showed combined allergy (type I/IV) to intracutaneous undiluted insulin. Whereas immediate and combined allergies were exclusively pure insulin allergies, several allergens were shown to be responsible in late reactions: nine patients had pure surfen allergy, 34 patients pure insulin allergy (against all insulins) and 11 pure bovine insulin allergy. A further 22 patients reacted to various allergens, 16 of them to surfen and all insulins, and 6 to surfen and bovine insulins. Estimation of the diameter of the erythema showed a significantly better skin tolerance of neutral than of acid insulins. Intracutaneous pig insulin led to less erythema than bovine insulin. Neutral pig insulins thus have the least antigenicity.