Complex regional pain syndrome (CRPS) happens when you experience intense, prolonged pain after an injury to an arm or a leg. It’s estimated that CRPS affects almost 200,000 people in the United States each year.
There are two types of CRPS:
- Type 1: Pain occurs in the absence of known nerve damage.
- Type 2: Pain occurs after a confirmed nerve injury.
Keep reading to learn more about CRPS, its symptoms, and how it’s treated.
CRPS symptoms often come on about 1 month after an injury to the affected limb.
The most common symptom of CRPS is pain that’s much more intense than it should be with your injury. You may experience this pain as:
With CRPS, you may also notice other changes in the affected limb, including:
- numbness and tingling, or a “pins and needles” sensation
- increased sensitivity to pain (allodynia)
- severe pain resulting from things that typically aren’t very painful (hyperalgesia)
- trouble with movement, including weakness or a reduced range of motion
Acute and chronic CRPS symptoms
Other CRPS symptoms can happen across two distinct phases: acute and chronic.
The acute phase is also referred to as the “warm” phase and happens early on. It’s characterized by deeper pain that gets worse with movement, as well as classic symptoms of inflammation in the affected limb, such as:
The chronic phase (or “cold” phase) starts
- a grayish or bluish appearance to the skin
- coldness and clamminess in the skin
- skin texture changes, in which the skin may appear shiny and thin or thick and scaly
- changes in the growth of hair and nails
- muscle tremors or spasms
- osteoporosis that affects nearby bones
As mentioned earlier, there are two types of CRPS:
- Type 1 CRPS: No specific nerve injury can be found. This type used to be called reflex sympathetic dystrophy.
- Type 2 CRPS: A known nerve injury is causing the symptoms. This type used to be called causalgia.
Whether the exact nerve injury is found or not,
Unlike other nerves in your body, the type of nerve fibers damaged in CRPS don’t have a protective myelin sheath. This makes them more prone to harm. These nerve fibers are important for a variety of functions, such as:
- carrying messages about sensations such as pain and temperature from your limbs to your brain
- controlling blood flow throughout the limb
- communicating with immune cells, particularly those involved in inflammation
When damage happens, the nerve fibers and tissues that they interact with may not function as they should, leading to symptoms of CRPS. Injuries or activities that can lead to CRPS include:
- bone fractures
- sprains or strains
- penetration injuries
- limb immobilization, such as when the limb is placed in a cast
Experts still are not sure why some people develop CRPS and others do not. Several factors, including various neurological, immune, and genetic causes, are likely involved.
There’s no single recommended treatment for CRPS. Treatment usually aims to alleviate symptoms and restore function to the affected limb.
The types of treatments used for CRPS can include a combination of the following:
- Physical therapy: A physical therapist will work with you to improve the function of your limb without making your symptoms worse. This may involve:
- physical therapy exercises that help boost your strength, flexibility, and range of motion
- mirror visual feedback and graded motor imagery that aim to retrain your brain in order to reduce pain and improve movement
- desensitization that lowers the sensitivity of the affected limb to various sensations
- Occupational therapy: An occupational therapist can help you develop strategies for better using your affected limb in daily activities.
- Neuropathic pain medications: Medications can also ease nerve pain associated with CRPS. Some medications that may be used include:
- epilepsy drugs like gabapentin and pregabalin
- tricyclic antidepressants like amitriptyline and nortriptyline
- Anti-inflammatory medications: Nonsteroidal anti-inflammatory drugs or corticosteroids can help reduce inflammation associated with CRPS.
- Bisphosphonates: Medications called bisphosphonates can reduce bone changes that happen with CRPS.
- Psychotherapy: Living with CRPS can cause mental and emotional strain, potentially leading to anxiety or depression. Psychotherapy can be beneficial in helping you cope.
- Nerve stimulation: If medications don’t reduce pain, nerve stimulation may help. This treatment involves using a device to send electrical signals to the affected nerves. It may include stimulation of the spinal cord, peripheral nerves, or other nerves.
Treatment is generally
The exact cause of CRPS isn’t well known, but some factors appear to increase the risk of developing CRPS after an injury, including:
- Sex: CRPS is more common in individuals assigned female at birth. Some research has found that this population is
four times more likelyto be diagnosed with CRPS.
- Age: CRPS appears to happen more frequently in people in early middle age. Most people are diagnosed
around age 40.
- Injury location: Injuries to the hand or arm appear to be more commonly involved in CRPS.
- Type of injury: Fractures are the
most commontype of injury associated with CRPS. Higher impact injuries, such as those sustained in a car accident or a fall, also appear to increase the risk of CRPS.
- Other disorders: Research suggests that a history of certain disorders may be associated with an increased risk of CRPS, including:
Having one or more risk factors for CRPS doesn’t mean you’ll definitely develop the condition after an injury. It means you may be at an increased risk for CRPS compared with others who do not have risk factors.
CRPS happens when you feel prolonged, excessive pain in a limb after an injury as a result of damage to nerves in that limb.
CRPS symptoms can gradually go away over months or years, but the condition can also have a debilitating long-term impact if you have severe symptoms.
Recovery may take longer if you experience problems with circulation or nutrition. Smoking, diabetes, and previous chemotherapy can also prolong recovery.
The outlook for CRPS is better if you start treatment soon after symptoms begin. Make an appointment with a doctor if you’ve recently had a limb injury and are having persistent pain that’s much more intense than usual.