Skin blood flow during histamine flare using the clearance of epicutaneous applied Xenon-133 in diabetic and non-diabetic subjects.

The increase in skin blood flow produced by both reactive hyperemia and histamine was examined in 8 normal, 8 diabetic and 3 cancer patients using the epicutaneous Xenon-133 clearance method. The histamine flare response in both diabetic and cancer groups was reduced compared to that in the normal group. There was no significant difference in the reactive hyperemia responses. It is concluded that the reduction in the histamine flare response is due to a defect in the sensory nerves mediating the axon reflex and not due to a change in the vascular response.