Complex Regional Pain Syndrome: Understanding Burning Pain After Injury

After a broken wrist, a sprained ankle, or even minor surgery, most people expect pain to fade over weeks. But for some, the pain doesn’t just stick around-it gets worse. It starts as a dull ache, then turns into a constant burning sensation, like your skin is on fire. A light touch, a breeze, or even a change in room temperature can feel unbearable. This isn’t normal healing. This is Complex Regional Pain Syndrome, or CRPS.

What Exactly Is CRPS?

CRPS is a neurological disorder that causes severe, long-lasting pain after an injury. It’s not just pain from damaged tissue-it’s pain from your nervous system going haywire. Your brain keeps receiving pain signals even when the injury has healed. This isn’t in your head. It’s a real, measurable dysfunction in how nerves communicate with your brain.

There are two types. Type I, which makes up about 90% of cases, happens after an injury with no clear nerve damage-like a fracture or sprain. Type II follows a confirmed nerve injury, such as from a cut or surgical complication. Both types cause the same symptoms: intense burning, throbbing, or stabbing pain that’s way out of proportion to what you’d expect.

CRPS usually affects arms or legs, but it can happen anywhere. It’s not rare-it’s just often missed. Around 20 to 50 people per 100,000 develop it each year in the UK. Women are three times more likely to get it than men, and it’s most common between ages 40 and 60. But younger people can get it too.

Why Does It Feel Like Fire?

The burning pain isn’t just a description-it’s what’s happening in your nerves. Tiny nerve fibers, called C-fibers, become overactive and send constant pain signals. Your spinal cord and brain start interpreting even harmless sensations as dangerous. This is called central sensitization. It’s like your nervous system’s alarm system got stuck on high volume.

Early on, the affected limb might feel warmer than the other side. Later, it can turn cold, pale, or blotchy. Skin becomes thin, shiny, and overly sensitive. You might notice hair or nails growing faster or slower than usual. Swelling, stiffness, and muscle spasms are common. Some people lose the ability to move their fingers or toes properly. The pain doesn’t just hurt-it makes everyday life impossible.

One key sign? Temperature differences between limbs. Studies show the affected limb can be 0.5°C to 1.5°C warmer or cooler than the healthy one. That’s enough for trained doctors to spot during an exam. If you’ve had an injury and your skin feels strangely hot or cold compared to the other side, that’s a red flag.

What Triggers CRPS?

CRPS doesn’t come out of nowhere. It usually starts after trauma. The most common trigger? Fractures. About 40% of cases follow a broken bone-especially wrist fractures. Other triggers include surgery (like carpal tunnel repair or knee arthroscopy), sprains, cuts, burns, or even a cast that’s too tight.

Here’s the puzzle: many people break bones or have surgery and never get CRPS. Why do some people develop it and others don’t? Scientists think it’s a mix of factors: inflammation, nerve damage, immune system overreaction, and maybe even genetics. A 2022 study found autoantibodies in 30% of CRPS patients-meaning the body’s own immune system might be attacking its nerves.

It’s not always obvious. About 10% of cases develop without any clear injury. Some people report pain starting after a simple bump or even a blood draw. That’s why doctors now say CRPS isn’t always triggered by trauma-it’s triggered by the body’s abnormal response to it.

How Is It Diagnosed?

There’s no blood test or X-ray that confirms CRPS. Diagnosis relies on the Budapest Criteria-a set of signs and symptoms doctors use to spot it. You must have:

• Pain that’s disproportionate to any initial injury
• At least one symptom in three of these four categories: sensory (burning, tingling), vasomotor (temperature or color changes), sudomotor/edema (swelling, sweating), and motor/trophic (weakness, tremors, nail/hair changes)
• No other diagnosis that better explains your symptoms

Early diagnosis is critical. If caught within the first three months, treatment has the best chance of stopping it from becoming permanent. After six months, the condition often hardens. Nerves become more damaged, muscles atrophy, and the brain’s pain map rewires itself. That’s why so many people end up with lifelong pain-they weren’t diagnosed early enough.

Treatment: What Actually Works?

There’s no magic pill. But early, aggressive treatment can change the outcome. The goal isn’t just to numb the pain-it’s to retrain your nervous system.

Physical therapy is the most important step. Moving the affected limb-even if it hurts-is proven to reduce long-term disability. Graded motor imagery and mirror therapy are two specialized techniques that help your brain “unlearn” the pain signal. A 2021 study showed patients who did daily mirror therapy for 8 weeks improved movement and reduced pain by over 50%.

Medications help manage symptoms. NSAIDs like ibuprofen can reduce early inflammation. Corticosteroids are sometimes used in the first few weeks. For nerve pain, gabapentin, pregabalin, or amitriptyline are common. Ketamine infusions are being tested in clinics for severe cases. Some patients get nerve blocks-shots that temporarily interrupt pain signals. Spinal cord stimulators, which send mild electrical pulses to block pain, are used for chronic cases.

But drugs alone won’t fix it. CRPS needs a team: a pain specialist, a physiotherapist, a psychologist, and sometimes a neurologist. Mental health matters. Chronic pain changes how you think, sleep, and feel about yourself. Anxiety and depression aren’t just side effects-they make the pain worse.

What’s the Long-Term Outlook?

Some people recover fully. Others live with pain for years. About 50% of cases improve significantly within a year if treated early. But if it’s ignored for six months or more, the chance of full recovery drops sharply.

It’s not hopeless. Many people learn to manage it. They find ways to move, sleep better, and reduce stress. They stop fighting the pain and start working with their bodies. That shift-from victim to manager-is often the turning point.

Research is moving fast. Scientists are testing new drugs that target inflammation and autoimmunity. Wearable sensors are being developed to detect early signs before pain becomes unbearable. The hope is that one day, we’ll be able to predict who’s at risk and stop CRPS before it starts.

What Should You Do If You Suspect CRPS?

If you’ve had an injury and your pain isn’t fading-if it’s burning, spreading, or getting worse with light touch-don’t wait. Don’t assume it’s just “slow healing.” Go to your GP or a pain clinic. Bring a list of your symptoms: when they started, what makes them better or worse, how your skin looks and feels.

Ask: Could this be CRPS? Many doctors still don’t know about it. If they dismiss you, ask for a referral to a specialist in neuropathic pain. Early action saves limbs, sleep, and sanity.

CRPS doesn’t have to be a life sentence. But it demands attention-right now.