Complex regional pain syndrome (CRPS) is a chronic, predominantly neuropathic and partly musculoskeletal pain disorder often associated with autonomic disturbances. It is divided into 2 types, reflecting the absence or presence of a nerve injury.
Patients with either type may exhibit symptoms such as burning pain, hyperalgesia, and/or allodynia with an element of musculoskeletal pain. CRPS can be distinguished from other types of neuropathic pain by the presence of regional spread as opposed to a pattern more consistent with neuralgia or peripheral neuropathy. Autonomic dysfunction (such as altered sweating, changes in skin color, or changes in skin temperature); trophic changes to the skin, hair, and nails; and altered motor function (such as weakness, muscle atrophy, decreased range of motion, paralysis, tremor, or spasticity) also can be present.
At least 50,000 new cases of CRPS are diagnosed in the United States annually.1 Although the incidence rate is subject to debate, a large epidemiologic study from The Netherlands involving 600,000 patients suggests an incidence of 26.2 per 100,000 individuals. The study also found that women are 3 times more likely to be affected, with postmenopausal women having the greatest risk.