[Allergy for human insulin]

In two patients, a man aged 55 years (patient A) and a man aged 67 years (patient B), severe immediate (type I) and severe delayed (type IV) local reactions to injections of human insulin, respectively, were diagnosed. There had been no previous treatment with insulin of animal origin. The diagnosis of type I allergy was based on the typical early local reaction with biphasic course, the positive immediate skin test and the raised specific IgE level against insulin. The diagnosis of type IV allergy was based on the characteristic late local reaction after 12 hrs, the delayed positive skin test and the negative specific IgE. The first attempt to desensitise patient A in 10 days was not successful, but he was desensitised successfully in 25 days. Patient B recovered spontaneously.