Cutaneous reactions of alloxan diabetic rats to local thermal trauma.

Thermal injury was induced on the external ears of nondiabetic and untreated alloxan diabetic rats of various ages. The skin reaction (erythema and necrosis) was assessed by naked eye inspection, 1, 7, 14 and 21 days after injury. Erythema was found to be more intense in young than in old controls after 1 and 7 days. The late erythematous reaction was more pronounced in short-term diabetic animals than in controls of the same age, indicating that the diabetic metabolic derangement per se alters the reaction. In addition, long-term diabetic rats had a markedly increased skin redness after 1, 7, 14 and 21 days when compared with controls of the same age. Thus, long-term diabetes enhances the erythematous reaction. As to the extent of necrosis, there was no significant differences between the experimental groups. There was, however, a tendency for an increased amount in the long-term when compared with the short-term diabetic rats.