Reflex sympathetic dystrophy (algoneurodystrophy): temperature studies in the upper limb.

The temperature response of the hands to mild cold stress (20 degrees C for one minute) has been measured in 20 normal subjects, 20 patients with reflex sympathetic dystrophy (RSD) and 10 patients with chronic upper limb pain (CULP) of uncertain origin. The results of RSD and CULP groups were significantly (p less than 0.05) different from normal but were indistinguishable. For each patient, 11 variables obtained from the thermal stress test were compared with the normal range. Ten of the RSD group and seven of the CULP group had four or more abnormal variables and were considered to have a thermoregulatory abnormality. The thermal stress test is useful in the objective assessment of RSD. It is non-invasive, patient acceptable and reproducible.