Haemodynamic changes in early phase reflex sympathetic dystrophy.

We studied six patients with early phase reflex sympathetic dystrophy (RSD). Osteoporotic changes were noted in the bones of the affected limb. Despite higher temperatures indicated by thermography, laser speckle image sensing showed no increase in blood flow on the skin surface. Digital subtraction angiography showed arteriovenous shunting or increased density of perfused vessels. Based on these results, we speculate that in RSD persistent vascular contraction caused by pain leads to the formation of arteriovenous shunts in the affected limb with an ischaemic state in the peripheral subcutaneous tissue which is indicated by pain and swelling.