by What is Complex Regional Pain Syndrome?
Complex regional pain syndrome (CRPS), previously known as reflex sympathetic dystrophy syndrome (RSDS), is a chronic pain condition that typically affects one limb (arm, leg, hand, or foot) usually after an injury or trauma to that limb. It is characterized by persistent severe and burning pain that is out of proportion to any inciting event. Other common features include swelling, changes in skin color or temperature, and/or excessive sweating in the affected region.
Causes and Risk Factors of CRPS
The exact cause of Complex Regional Pain Syndrome is unknown, but it often develops after an injury, surgery, heart attack or stroke. Common causes include fractures, sprains, soft tissue injuries like contusions, injections, burns and frostbites. CRPS tends to develop more often in women than men and usually occurs in those between the ages of 40-60. Individuals with a personal or family history of migraines, anxiety or depression may also be at a slightly higher risk. Genetic factors may also play a role in some cases.
Symptoms of CRPS
In addition to persistent, severe burning pain, common CRPS symptoms include:
– Skin color changes: The skin may appear blotchy, mottled or change color to become purplish, bluish or reddish in the affected area.
– Temperature changes: The skin temperature in the affected area may feel warmer or cooler than the other side. Thermography tests often show significant temperature differences between the two sides.
– Sweating changes: The affected area may sweat more or less than the opposite side.
– Soft tissue swelling: Edema or swelling in the affected wrist, hand, ankle or foot is very common.
– Stiffness: Range of motion often decreases in the joints of the affected limb due to joint stiffness.
– Motor dysfunction: Tremors or involuntary muscle contractions can occur in the limb with CRPS.
Diagnosing Complex Regional Pain Syndrome
There is no single test to definitively diagnose Complex Regional Pain Syndrome. Doctors will consider the patient’s medical history and do a physical exam looking for signs of pain, changes in skin temperature, color, texture or sweating in the affected area. Diagnostic criteria involve the presence of one or more signs in each of the four categories:
1. Sensory – Reports of hyperalgesia (increased pain from stimuli) and/or allodynia (pain from stimuli that do not normally cause pain like clothes or wind)
2. Vasomotor – Reports of temperature asymmetry and/or skin color changes and/or skin color asymmetry
3. Sudomotor/Edema – Reports of edema and/or sweating changes and/or sweating asymmetry
4. Motor/trophic – Reports of decreased range of motion and/or motor dysfunction and/or trophic changes
The symptoms must not be explained by another condition. Tests such as X-rays, MRI, bone scans or thermography may support the diagnosis but are not required for diagnosis.
Treating Complex Regional Syndrome
Unfortunately, there is no cure for CRPS and the most effective treatment is often a multidisciplinary approach involving medications, physical/occupational therapy, pain management techniques and in some cases surgery.
Medications: Oral medications commonly used include over-the-counter NSAIDs, tricyclic antidepressants, anticonvulsants and topical lidocaine patches. For more severe cases, infusions of IV medications, corticosteroids, regional anesthetics or ketamine may be considered.
Physical/Occupational Therapy: Gentle range of motion and desensitization exercises performed several times per day under the guidance of a physical or occupational therapist are important. The goal is to improve function while avoiding further sensitization of the nerves.
Pain Management: Techniques such as cold/heat therapy, TENS unit, acupuncture or hypnosis may help manage pain levels. In some cases, nerve blocks or spinal cord stimulators may be helpful.
Surgery: Surgical sympathectomy to sever certain sympathetic nerves supplying the affected area is sometimes performed for severe cases, but success rates are variable.
The prognosis for CRPS patients is highly variable, but early diagnosis and a multidisciplinary treatment approach provides the best chance for optimal outcomes, including reduced pain levels and improved limb function. In the most severe cases, chronic pain and disability may persist long-term despite treatments. With proper management though, many patients experience significant relief of their CRPS symptoms over time.
*Note:
1. Source: Coherent Market Insights, Public sources, Desk research
2. We have leveraged AI tools to mine information and compile it
