Comparison of resting capillary flow dynamics in the finger and toe nailfolds.

The purpose of this study was to compare capillary dynamics in the nailfold regions of the human toes and fingers. Capillary blood flow velocity (VEL), vessel diameter, the total number of capillaries and the number of capillaries with active flow per mm2 of tissue were measured in the toe nailfold region of 17 and in the finger nailfolds of 15 male subjects 20 to 40 years of age. All measurements were made in the rest state at a skin temperature of 32 degrees C. Group averages were: (Formula: see text). These results demonstrate that compared to the finger the nailfold capillaries in the toe have a lower blood flow per vessel but a much higher capillary density. The combination of these factors indicates that total capillary blood flow is higher in the toe nailfold system.