Definition
Complex Regional Pain Syndrome (CRPS) is the term used to describe pain and swelling in one part of the body. CRPS usually affects the hands, feet, elbows or knees, but can affect any part of the body.
The pain may start after an injury, where the nerves have been damaged, or there may be no known cause for it to start. The pain usually gets gradually worse and may spread to other parts of the body.
Types of CRPS
There are two types of CRPS that have different causes. They are:
- Type one CRPS is triggered by a simple injury, such as a sprained or fractured ankle, where there has not been any nerve damage.
- Type two CRPS is triggered by a more serious injury or procedure, where nerve damage has occurred following, for example, a broken bone, a serious infection or an operation
The injury causes pain that is much worse than expected. About 90% of all cases of CRPS are type one CRPS.
Symptoms
The main symptom of chronic regional pain syndrome (CRPS) is a severe, continuous burning pain in part or all of a limb. This could be in one of your arms, legs, hands, feet or ankles.
The pain is usually triggered by an injury, and is a lot worse than you would normally expect. For example, you may have a minor ankle sprain, but the pain can feel like a severe burn.
If you have CRPS, the skin of the affected body part can become very sensitive, and even the slightest touch, bump, or change in temperature can provoke a feeling of intense pain.
You may hear this described in the following medical terms:
- hyperalgesia – when you are extremely sensitive to pain
- allodynia – when you feel pain from something that should not be painful at all, such as a very light touch
In more severe cases of CRPS, the muscles in the affected limb may begin to wither (atrophy). This usually occurs if the person affected is unwilling to use their limb due to the associated pain.
Other symptoms
CRPS can cause some other symptoms, including:
- alternating changes in skin temperature – sometimes your skin may feel sweaty, while at other times it may feel cold and clammy
- changes in skin colour – your skin tone may range from pale and colourless to pink, or it may have a blue tinge and appear blotchy or streaky
- changes in skin texture – your skin may appear shiny and thin
- changes in the way that your hair and nails grow – they may grow unusually slowly or unusually quickly
- swelling, pain and stiffness in the affected joints
- increasing difficulty moving the affected body part
