CRPS patients are referred with a diagnosis of CRPS-I or CRPS-II in one limb only, based on pain (1) that is post-traumatic and spread beyond the region of the injury; (2) has persisted for more than 2 weeks; and (3) is associated with swelling, altered skin color or skin temperature, altered sweating, allodynia or hyperesthesia or limitation of active movement. Atrophic changes in skin, hair loss or nail changes, or disuse atrophy of skeletal muscle may be present.