What is CRPS?

Complex Regional Pain Syndrome (CRPS), also known as Reflex Sympathetic Dystrophy, is a chronic neurological syndrome characterized by:

• severe burning pain
• pathological changes in bone and skin
• excessive sweating
• tissue swelling
• extreme sensitivity to touch

There are Two Types of CRPS - Type I and Type II

• CRPS Type I (also referred to as RSD) - cases in which the nerve injury cannot be immediately identified
• CRPS Type II (also referred to as Causalgia) - cases in which a distinct "major" nerve injury has occurred
• CRPS is best described in terms of an injury to a nerve or soft tissue (e.g. broken bone) that does not follow the normal healing path
• CRPS development does not appear to depend on the magnitude of the injury. The sympathetic nervous system seems to assume an abnormal function after an injury.
• Since there is no single laboratory test to diagnose CRPS, the physician must assess and document both subjective complaints (medical history) and, if present, objective findings (physical examination).

Criteria for Diagnosing
Complex Regional Pain Syndrome Type I (RSD)

• The presence of an initiating noxious event, or a cause of immobilization
• Continuing pain, allodynia, or hyperalgesia with which the pain is disproportionate to any inciting event
• Evidence at some time of edema, changes in skin blood flow (skin color changes, skin temperature changes more than 1.1°C difference from the homologous body part), or abnormal sudomotor activity in the region of the pain
• This diagnosis is excluded by the existence of conditions that would otherwise account for the degree of pain and dysfunction

Complex Regional Pain Syndrome Type II (Causalgia)

• The presence of continuing pain, allodynia, or hyperalgesia after a nerve injury, not necessarily limited to the distribution of the injured nerve
• Evidence at some time of edema, changes in skin blood flow (skin color changes, skin temperature changes more than 1.1°C difference from the homologous body part), or abnormal sudomotor activity in the region of pain
• This diagnosis is excluded by the existence of conditions that would otherwise account for the degree of pain and dysfunction.

Complex Regional Pain Syndrome (CRPS) is poorly understood by patients, their families, and healthcare professionals. In some cases the condition is mild, in some it is moderate, and in others it is severe. We have compiled a list of some of the common misconceptions about this syndrome followed by the facts.

CRPS Fact Sheet

• Complex Regional Pain Syndrome (CRPS), also known as Reflex Sympathetic Dystrophy (RSD), is a chronic pain syndrome characterized by severe and relentless pain that affects between 200,000 and 1.2 million Americans.
• CRPS is a malfunction of part of the nervous system. Nerves misfire, sending constant pain signals to the brain. It develops in response to an event the body regards as traumatic, such as an accident or a medical procedure. This syndrome may follow 5% of all nerve injuries.1,2
• Minor injuries, such as a sprain or a fall are frequent causes of CRPS. One characteristic of CRPS is that the pain is more severe than expected for the type of injury that occurred.
• Early and accurate diagnosis and appropriate treatment are key to recovery, yet many health care professionals and consumers are unaware of its signs and symptoms. Typically, people with CRPS report seeing an average of five physicians before being accurately diagnosed.
• Symptoms include persistent moderate-to-severe pain, swelling, abnormal skin color changes, skin temperature, sweating, limited range of movement, movement disorders.
• CRPS is two to three times more frequent in females than males.
• The mean age at diagnosis is 42 years. However, we are seeing more injuries among young girls, and children as young as 3 years old can get CRPS.
• This is not a psychological syndrome, but people may develop psychological problems when physicians, family, friends, and co-workers do not believe their complaints of pain.
• Treatments include medication, physical therapy, psychological support, sympathetic nerve blocks, and or spinal cord stimulation.

1. Loeser JD. Ed. Bonica's the management of pain. 3rd Ed. Philadelphia, PA: Lippincott, Williams, & Wilkins; 2001:388-411.
2. Plewes LW. Sudek's Atrophy in the Hands. J Bone Joint Surg. 1956;38:195-203.