Microcirculatory response of skin to benzoic acid and methyl nicotinate inpatients 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 exa mine the microvascular response of upper arm skin to non-immunological cont act irritants in 17 insulin-dependent diabetic patients and 11 non-diabetic controls. Methods Non-immunological contact urticaria, an inflammatory reaction media ted in a unique way, not previously studied in diabetic patients, was exami ned. The test agents were benzoic acid and methyl nicotinate. The intensity of the reactions was measured using laser-Doppler flowmetry and colorimetr y. 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 betwe en the groups, but the diabetic patients showed increased blood flow respon ses to the lowest irritant concentrations compared to the controls. The rea ctions 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.