One or more limbs of the body suffer from complex regional pain syndrome (CRPS), a chronic condition that usually results from injury or illness. Aside from causing severe pain, CRPS can also cause changes to the skin, muscles, joints, and bones of the affected limb. It is unclear what causes CRPS, but it may be related to abnormal nerve responses and inflammation. CRPS is rare and can affect anyone, but it is more common in women and people over the age of 40.
CRPS can occur after any type of injury or illness that affects a limb, such as:
Fractures
Sprains
Burns
Cuts
Surgeries
Infections
Strokes
Heart attacks
However, not everyone who has these conditions develops CRPS. The exact trigger of CRPS is unknown, but it may involve:
Damage to the nerves or blood vessels of the affected limb
Abnormal activation of the sympathetic nervous system, which controls blood flow and temperature
Excessive release of inflammatory substances and immune cells
Genetic factors that make some people more susceptible
The main symptom of CRPS is intense, burning, or throbbing pain in the affected limb. The pain may spread to other parts of the body, such as the opposite limb or the trunk. The pain may be triggered or worsened by touch, movement, or temperature changes. Other symptoms of CRPS may include:
Swelling and stiffness of the affected limb
Changes in skin color, temperature, and texture
Changes in hair and nail growth
Muscle spasms, weakness, and atrophy
Joint deformity and damage
Reduced ability to move the affected limb
It is possible for CRPS symptoms to improve or worsen over time and from person to person. Some people may experience remission while others may experience persistent or progressive symptoms.
The diagnosis of CRPS is based on the medical history, physical examination, and exclusion of other conditions that may cause similar symptoms. Some tests that may confirm the diagnosis or rule out other conditions include:
Bone scan: This test uses a radioactive substance to show bone changes in the affected limb.
X-ray: This test can detect bone loss or fractures in the affected limb.
MRI: This test can show tissue changes or damage in the affected limb.
Sweat production test: This test can measure the amount of sweat on both limbs. Uneven results may indicate CRPS.
Sympathetic nerve block: This test involves injecting an anesthetic to block the pain signals from the affected limb. If the pain is relieved, it may suggest CRPS.
The treatment of CRPS is usually multidisciplinary, including different types of therapies and medications. The treatment goals are to:
Relieve pain and inflammation
Improve blood flow and nerve function
Restore mobility and function of the affected limb
Prevent or reverse tissue changes and bone loss
Enhance quality of life and psychological well-being
Some of the treatment options for CRPS are:
The pain relievers include over-the-counter medications such as aspirin, ibuprofen, or naproxen, as well as prescription medications such as opioids, antidepressants, and anticonvulsants.
Corticosteroids: These medications can help reduce swelling and improve mobility in the affected limb.
Bone-loss medications: These medications can help prevent or slow down bone loss in the affected limb. They may include alendronate or calcitonin.
Anesthesia or oral medications, such as prazosin, phenoxybenzamine, or clonidine, can block the pain signals from the affected limb.
Intravenous ketamine: This medication is a strong anesthetic that may help reduce pain in some cases of CRPS. It is given in low doses through a vein.
Exercises, massage, stretching, splinting, and electrical stimulation can help improve the movement and function of the affected limb.
Heat therapy: This therapy can help relieve swelling and discomfort in the affected limb. It may involve applying warm compresses, heating pads, or hot water bottles.
Topical analgesics: These medications can help reduce hypersensitivity in the affected limb. They may include creams, gels, or patches that contain capsaicin or lidocaine.
Counseling, cognitive-behavioral therapy, relaxation techniques, and biofeedback can all be used to cope with the emotional and psychological effects of CRPS.
Spinal cord stimulation: This therapy involves implanting a device that delivers electrical impulses to the spinal cord. It may help block the pain signals from the affected limb.
Surgery: This therapy is rarely used and only in severe cases of CRPS. It may involve cutting or destroying the nerves or blood vessels that are causing the pain.
There is no sure way to prevent CRPS, but some measures that may help reduce the risk or severity of the condition are:
Seeking prompt and proper treatment for any injury or illness that affects a limb
Taking pain relievers and anti-inflammatory drugs as prescribed after an injury or surgery
Moving and exercising the affected limb as soon as possible after an injury or surgery
Avoiding smoking, alcohol, caffeine, and stress, which may worsen the symptoms of CRPS
Seeking psychological support if needed to deal with the emotional and mental impact of CRPS
In addition to severe pain and changes in the affected limb, complex regional pain syndrome (CRPS) is a chronic and debilitating condition. According to the medical history, physical examination, and exclusion of other conditions, CRPS is caused by nerve damage, inflammation, and abnormal nerve responses, but the cause is unclear. CRPS is usually treated by a multidisciplinary team that aims to relieve pain, improve function, and prevent complications. It is possible to improve the outcome and quality of life of people with CRPS by treating them early and aggressively.
