Microcirculatory response of skin to benzoic acid and methyl nicotinate in patients with diabetes

Aims In view of the relationship between microvascular pathology and organ complications in diabetes mellitus, the aim of the present study was to examine the microvascular response of upper arm skin to non-immunological contact irritants in 17 insulin-dependent diabetic patients and 11 non-diabetic controls. Methods Non-immunological contact urticaria, an inflammatory reaction mediated in a unique way, not previously studied in diabetic patients, was examined. The test agents were benzoic acid and methyl nicotinate. The intensity of the reactions was measured using laser-Doppler flowmetry and colorimetry. The patients were divided into two groups, depending on whether they had had diabetes for less or more than 10 years. Results There were no differences in the maximal blood flow responses between the groups, but the diabetic patients showed increased blood flow responses to the lowest irritant concentrations compared to the controls. The reactions in the two groups of diabetic patients were similar. Conclusions The present study suggests that the microvascular reactivity of diabetic skin to non-immunological contact irritants is increased.