Intradermal desensitization with human insulin (recombinant DNA) in a patient with severe allergic skin reaction due to insulin.

This is a case report of a 70-yr-old female patient with a severe allergic skin reaction (necroses) due to insulin injections. Because of insulin dependency, desensitization to insulin was mandatory. For desensitization, a schedule with intradermal injections of increasing insulin concentrations (from 0.02 to 2 U per injection) at time intervals of 3 h was used. With highly purified pork insulin, the concentration limit of 0.04 U was reached in spite of 75 injections. After changing to human insulin (recombinant DNA), a rapid desensitization could be performed at the same concentration. Desensitization resulted not only to human insulin but also to highly purified pork insulin, as shown by intradermal testing 6 mo later.