Epidermal skin thickness and vascular density were assessed in skin biopsies obtained from the dorsum of the foot in 28 Type 1 diabetic patients and 17 normal control subjects, matched for age. Epidermal skin thickness did not differ significantly between control subjects (74 +/- 4 (+/- SE) microns) and diabetic patients (78 +/- 4 microns). It was not related to the duration of diabetes and presence of complications. Neither small (capillary) nor large (arteriole/venule) vessel densities differed significantly between control subjects (59 +/- 6 mm-2 and 19 +/- 2 mm-2) and diabetic patients (65 +/- 4 mm-2 and 22 +/- 3 mm-2). Vessel densities were unrelated to the duration of diabetes and presence of complications.