Lipoatrophy induced by recombinant human insulin injection.

A 79-year-old man had been treated with recombinant human insulin since the age of 77. He developed subcutaneous fat atrophy around the injection site 16 months after induction of insulin therapy. Skin biopsy of the atrophic site revealed inflammatory changes and adipocyte atrophy. Changing the type of insulin and injection site relieved the fat atrophy. Although insulin-induced lipoatrophy was a common complication before the development of human insulin, it is now rare. The immunological reaction to the insulin product, as in conventional impure insulin-induced lipoatrophy, seemed to be involved in the etiology of lipoatrophy in this case.