Reflex sympathetic dystrophy Dr Rob Hicks A rare but distressing malfunction of the nervous system.

In this article

What is reflex sympathetic dystrophy (RSD)? Symptoms

Causes and risk factors Treatment and recovery

Advice and support

Reflex sympathetic dystrophy (RSD) involves a malfunction of the nervous system that causes pain (often diffuse, intense and unrelenting) and related sensory abnormalities.

There may also be abnormal blood flow and sweating in the affected area, problems with movement of the muscles and changes in the structure of the tissues ('trophic' changes). It has been known by many names but is now most commonly known as RSD or complex regional pain syndrome type 1 (CRPS 1).

The process of RSD involves three stages:

• The initial acute stage, which may last up to a few months, causes pain, often described as burning, and excess sweating in the affected part of the limb, which also becomes warm and red. During this stage, someone with RSD may notice their hair and nails grow faster than usual. The joints of the affected limb may also become painful.
• Stage two can last up to a year and is known as the dystrophic stage. The affected limb may be constantly swollen, causing wrinkles in the skin to disappear. Fingernails become brittle, and the pain and stiffness spread up the limb and along the same side of the body, or may spread to the opposite limb.
• After a year, RSD enters stage three - the atrophic stage. The muscles may waste away and the skin usually becomes stretched, shiny and pale. The pain may lessen but is constant, and the part of the body affected is stiff. The skin may also be hypersensitive to touch. Once this stage has been reached, the chance of recovering movement diminishes.

Because of the long-term nature of RSD and its symptoms, depression often develops.

RSD often develops following some sort of initiating event, such as an injury or immobilisation of part of the body (for example after an accident where a limb is broken and then put in a plaster cast.)

Even minor injuries can be responsible, with continuing pain or uncomfortable sensations that seem out of proportion to the initial injury.

RSD may occur because the part of the nervous system that controls blood flow and sweat glands in the hand and arm is disturbed and becomes overactive. Burning pain, swelling, stiffness and discolouration of the hand or other extremities develop.

Infection, pressure on a nerve, heart attack, stroke or surgery may also trigger RSD, although the mechanism is not clear.

But there may be no obvious injury to the nerves to explain the symptoms and often the exact reason for RSD remains a mystery.

Women are more likely to develop RSD, but the condition affects people of any age, including children.

If identified early, RSD is treatable.

Treatment is aimed at controlling pain, enabling the person to regain or improve the function of the affected limb, and providing emotional support.

In early stages, a course of steroid tablets have been shown to be effective, reducing inflammation and bringing pain relief. Nerve blocks are also effective - these are injections of local anaesthetic into the affected nerve (if one can be identified).

A number of other medicines may also be used to relieve symptoms, including painkillers and drugs such as amitriptyline, which is most commonly used to treat depression but can treat nerve pain too. Other drugs that may be prescribed include gabapentin.

Most patients benefit from being treated, if possible, in a specialised pain clinic where they can be given a wide variety of treatments and psychological support.

Physiotherapy is important to help regain function and relieve symptoms. Occupational therapy can help someone learn how to overcome the difficulties they're facing with everyday activities.

If RSD has progressed significantly, surgery may be recommended.

RSD UK Alliance
Website: www.rsdalert.co.uk

This article was last medically reviewed by Dr Trisha Macnair in August 2009.