Use of thermography for initial detection of early reflex sympathetic dystrophy.

Reflex sympathetic dystrophy is one of a complex of overlapping, sympathetically maintained pain syndromes which are usually initiated by a minor injury that resolves quickly but leaves behind a persistent pain that generalizes to much or all of the limb. The pathophysiology of reflex sympathetic dystrophy is reviewed to show that the pain is accompanied by cooling of the limb, beginning with the distal end and gradually progressing throughout. Thermography is shown to be an effective way to monitor near-surface blood flow in the limbs and to be sensitive to changes accompanying painful conditions. The usefulness of this technique for early detection of reflex sympathetic dystrophy is demonstrated and illustrated with several examples.