A Peculiar Cutaneous Reaction to Repeated Injections of Insulin

A bizarre skin lesion consisting of a collection of brown, hyperkeratotic papules appeared on the thighs of a 51-year-old diabetic man, after repeated insulin injections into the same area over a period of two or more years. The reason for the development of this type of lesion instead of the usual lipodystrophy that follows multiple insulin injections is obscure.