Complex regional pain syndrome
A person with complex regional pain syndrome (CRPS) will experience continuous severe pain in one of their limbs. It normally begins as an overreaction to an injury. Although there is no cure for the condition, a combination of treatments can help manage it.
What is complex regional pain syndrome?
When CRPS occurs the body has a strong reaction to an injury resulting in on-going severe pain. This response to the injury is much stronger that it should be. It usually occurs in only one limb, and although occasionally the whole limb can be affected, it most often occurs in a hand and wrist, a foot and ankle, or a knee.
There are two types of complex regional pain syndrome:
- CRPS I (sometimes known as reflex sympathetic dystrophy/RSD or Sudeck's syndrome) - pain develops although there is an absence of identifiable injury to any nerves. It follows an injury such as a sprain or fracture.
- CRPS II (sometimes known as causalgia) - pain develops after damage to a nerve in the limb.
Regardless of the type, diagnosis and treatment are the same. Although CRPS often improves, or gets completely better, over time, sometimes it never disappears.
What are the causes of complex regional pain syndrome?
It is not known exactly what causes CRPS but it is often triggered by a bone fracture or other injury such as a sprain, strain, burn or cut. Although the cut may have occurred to a finger, the pain can spread to the whole arm. Sometimes a stroke or having a number of operations on a limb can be a trigger. Having a limb in a plaster cast or otherwise immobilised can also trigger CRPS, as can prolonged bed rest. In about 1 in 10 cases CRPS develops without any trigger being identified.
Experts believe that the condition could occur because the nerves in the affected area are more sensitive than they should be, and the pain pathways between them and the brain are altered somehow, affecting how the brain communicates with the affected limb. If this happens, long after the original injury has healed, the pain continues. Other theories include a malfunction in the immune system or blood vessels.