Complex regional pain syndrome

Also called CRPS, Reflex sympathetic dystrophy

Pain wildly out of proportion to the injury that started it, with visible changes in the limb. Early movement is the treatment, and the delay is what does the damage.

What it is

A persistent, severe pain condition affecting a limb, usually after an injury, fracture or operation that may have been minor.

What separates it from ordinary post-injury pain is the disproportion and the visible changes: the limb looks and behaves differently. Colour, temperature, sweating, swelling, hair and nail growth all alter, and the skin can become so sensitive that a sleeve or a breeze is unbearable.

It is a disorder of how the nervous system processes signals rather than ongoing tissue damage. That does not make it psychological, and people with CRPS are told it is more often than almost any other group in this library.

Early diagnosis and early movement give much the best outcome. Left immobile, the limb stiffens, weakens and becomes harder to use, which increases pain, which increases immobility. Breaking that loop early is the whole game.

Most people improve substantially, particularly with treatment in the first year. A minority have long-term disability.

Signs you might notice

Burning, aching or stabbing pain out of proportion to the injury, and lasting beyond the expected healing time.

Extreme sensitivity: light touch, clothing or temperature change causing severe pain.

Changes in the limb: swelling, colour change from red to blue or mottled, feeling hotter or colder than the other side, sweating differences.

Changes in hair, nail and skin texture.

Stiffness, weakness, tremor, and difficulty starting movement.

The limb feeling foreign, or hard to picture in the mind.

Worth acting on early: pain and swelling after a fracture that is not settling as expected, especially with colour or temperature change. Say the words complex regional pain syndrome.

How it can affect day-to-day life

Being disbelieved is close to universal, and it is clinically important: people who are told it is in their mind stop moving the limb and do worse.

The sensitivity makes ordinary life hard in ways that are hard to convey: bedding, showers, a coat sleeve, someone brushing past on a bus.

Because it often follows a minor injury, employers, insurers and families frequently do not accept the scale of the disability.

Sleep, mood and function all deteriorate together, and treating depression and anxiety alongside is part of pain management rather than an alternative to it.

Specialist pain services and rehabilitation programmes exist and waiting times are long, which is another argument for referring early.

Supporting someone well

Keep the limb moving from the start, within what is tolerable. Immobilising it is the single most harmful thing.

Ask for referral to a specialist pain service early, ideally within weeks rather than months.

Ask for physiotherapy and occupational therapy experienced in CRPS; graded motor imagery and desensitisation are specific techniques that help.

Take the pain seriously and say so out loud. Believing the person is part of the treatment.

Ask about nerve pain medicines rather than ordinary painkillers, which usually do little here.

Use the limb in daily tasks rather than protecting it, building up gradually.

Address sleep and mood in their own right.

Where to get help

A GP practice, asking for referral to a specialist pain service.

The fracture clinic or surgeon if it followed an operation or injury; they can refer directly.

Arthritis UK and the pain charities publish self-management material that applies here.

British Pain Society list specialist pain services.