Disturbance of thermoregulatory skin perfusion in reflex sympathetic dystrophy

Patients with reflex sympathetic dystrophy (RSD) were examined for their neurovascular functions (n = 27). At the time of investigation the median duration of the disease was 8 weeks (2 - 100). Patients with signs and symptoms of the disease of less than 8 weeks were classified as acute RSD (n = 14) and patients with signs and symptoms of more than 8 weeks as chronic RSD (n = 13). For control, healthy subjects were investigated (n = 19). After acclimatisation for 2 hours, the skin temperature was measured simultaneously at the affected and unaffected limb by infrared thermography. After baseline recording for 2 minutes the limbs were immersed in cold water (5 degrees C) and rewarming was registered. The control group showed no side differences concerning skin temperature and rewarming. The acute RSD patients showed significant warmer skin temperatures at rest at the affected limb (p < 0.001), and rewarming occurred significantly faster on the affected side (p < 0.03). In contrast, the chronic RSD patients showed no side differences. Concerning the total patient group, a significant correlation between side differences of skin temperature and duration of symptoms was found (p < 0.002). There was a barely significant correlation between side differences of rewarming and duration of disease (p = 0.06). Our results demonstrate a marked disturbance of autonomic control of skin perfusion at the affected extremity in acute RSD patients. Higher skin temperature at rest and faster rewarming after cold water immersion indicate a lower sympathetic tone of the affected extremity. Such side differences disappear in the course of disease.