Complex regional pain syndrome - The facts explained

Pain usually develops after an injury, which is often quite minor and innocuous. The pain experienced is often completely out of proportion to the injury itself.

Frequency and causes

It was previously thought that CRPS was a psychosomatic condition and that the symptoms of pain were simply “all in the mind”. Research has now disproved this theory as it has been shown that there are real physical changes in the nervous system of CRPS sufferers.

The cause of CRPS is still relatively unknown which could explain why initially people thought the condition was psychosomatic. Research is still on-going in this area but the current consensus is the condition is linked to an abnormal neural response to injury. Something causes certain nerves to misfire in some way triggering pain – but that something still eludes the researchers.

Symptoms of CRPS

• Pain – usually triggered by an injury. The pain is severe and is often a lot worse than the injury would suggest.
• Allodynia - The skin of the affected limb can become very sensitive and the body interprets light touch and temperature changes as pain
• Alternating changes in skin temperature changing from hot and sweaty to cold and clammy
• Skin colour may change from normal to either; pale and colourless or tinged, pink or blue and may appear blotchy.
• Skin texture may change and the skin may appear shiny and thin
• Hair and nail growth is altered either unusually slowly or quickly
• Often there is swelling and stiffness in the affected joints. 

Diagnosis

There is no single test to confirm CRPS. Often the diagnosis is reached by a process of elimination, ruling out other conditions that have similar symptoms.

There are tests that can give a good indication that you have developed CRPS such as:

• Sweat testing- the sweat produced by an unaffected limb and affected limb is measured. A large difference between the two readings could indicate CRPS
• Thermography – an infrared thermometer is used to measure skin temperature of an affected and unaffected limb. The unaffected limb can be a higher or lower temperature than the unaffected limb possibly indicating CRPS

Who’s likely to be affected?

• It's difficult to quantify accurately as CRPS is often mis-diagnosed or undiagnosed.
• 3 out of 4 cases occur in women
• One study reported 1 in 3800 people in England may be affected
• CRPS can begin at any age – however the average age for symptoms to start is 40

Treatment

The complex nature of CRPS means it is often treated by a multi-disciplinary team such as a chronic pain team. A chronic pain team may consist of a physiotherapist, neuorologist, psychologist, pharmacist and more.

Physiotherapy is often viewed as one of the most beneficial modalities as it can restore function and movement to the affected body part by preventing muscle wastage and improving confidence.

Response to treatment is very mixed and depends on the individual. Success will vary from a return to functional movement and a return to work or simply reduced pain medication intake. Although results can vary greatly, a pain management team should always be engaged at the earliest stage post diagnosis to maximise the potential chance of success.

Summary

It is clear more research needs to be done into CRPS. There is greater awareness of the condition amongst the medical profession now so fewer cases are being missed or wrongly diagnosed. Although the knowledge base for this conditition is small at least it has been accepted that it is real and no longer psychosomatic.   

http://www.nhs.uk/Conditions/Complex-Regional-Pain-Syndrome/Pages/Treatment.aspx