Pain is more often a symptom of illness or injury than a condition in and of itself. But what if your only real symptom is pain? Most pain conditions can be traced back to some nociceptive or neurological cause, but some conditions and cases are more complex to diagnose than others. One such pain condition is complex regional pain syndrome (CRPS), a collection of inflammatory and pain symptoms that can often last for months and become chronically debilitating. Previously known as causalgia or reflex sympathetic dystrophy (RSD), CRPS is characterized by debilitating and spontaneous pain following a mild touch or other forms of physical contact, usually in the arms or legs. In addition to pain, CPRS may include changes in skin color and temperature, temporary swelling under an old injury site, and more.
What Is Complex Regional Pain Syndrome (CRPS)?
As far as we understand, complex regional pain syndrome begins after an area of the body was previously injured and is primarily neurological. The peripheral nerves surrounding the injured area responsible for carrying pain messages to the brain may be damaged during the healing process or heal improperly, causing prolonged inflammation and heightened pain sensitivity because the nerves continue to promote healing even after the rest of the tissue has recovered. When an injury occurs, whether it’s a sprain, a broken bone, or physical trauma against the skin and muscles, the body uses inflammation to promote healing and speed up tissue rebuilding.
Pain sensitivity is also an essential part of the healing process – you may have noticed that when you cut yourself or hurt your arm, the affected area becomes tender. Even a slight brush of your finger can be uncomfortable. In cases of complex regional pain syndrome, improper healing or nerve damage can cause the peripheral nerves in the body to continue to try and boost pain sensitivity and promote inflammation, despite the injury itself being long gone. Complex regional pain syndrome can be split into two different types:
CRPS I is diagnosed when there is no confirmed nerve injury, but all symptoms point towards a case of complex regional pain syndrome.
When a nerve injury is confirmed or discovered, the diagnosis is changed to CRPS II. These are functionally the same condition, but a distinction is made depending on whether a patient’s nerve damage has been determined. In many cases, damage to motor nerves can make it easier to identify CRPS II, resulting in weakness, loss of strength, mobility issues, disability, and muscle shrinkage because of the injury.
Age is an important factor here – elderly patients are less likely to experience complex regional pain syndrome as the body heals slowly and does not promote inflammation as effectively. At the same time, children are also unlikely to experience CRPS because they heal very quickly. Most patients with CRPS are adults, and the risk peak is around age 40. However, there are always exceptions to the rule. Anybody can experience CRPS at any age. About 200,000 people are diagnosed with CRPS per year in the United States. In general, women are more likely to struggle with CRPS than men.
How Does It Start?
Complex regional pain syndrome is diagnosed after an injury but does not necessarily mean physical trauma. It can develop due to surgery or after a heart attack or stroke, and occur after a burn, a cut, a piercing wound (if it hits specific nerves), bone fractures, and so on. A previous illness or condition is usually a prerequisite for CRPS. Only about 10 percent of cases report no causal injury. In these cases, some other condition may be causing the prerequisite nerve damage. What sets CRPS aside from typical post-injury pain is:
- The severity of pain is disproportionate to the original injury (meaning, it is significantly worse than it should be).
- Pain can be chronic and debilitating, even after the injury has healed or other forms of physical recovery have been completed.
It is important to note that while the medical community has made strides in identifying, communicating, and classifying examples of complex regional pain syndrome, this is still a condition that is only rarely identified and not completely understood. Most cases occur after an area’s “small fiber” nerves are damaged. These smaller nerves lack the myelin sheathing of larger nerves, meaning they are not as well-protected as the rest of our peripheral nervous system and are primarily responsible for transmitting information like pain, itching, and temperature. The primary culprit behind CRPS is nerve damage, usually due to a previous injury, physical trauma, or condition. Please see your doctor if:
- Your pain is extreme, even for the injury you’ve suffered.
- The affected area continues to be extremely sensitive, especially to touch and temperature.
- There is significant swelling and/or discoloration in the area.
- Your skin texture changes (i.e., your skin is exceptionally smooth or shiny around the affected area).
- You’re experiencing significant joint stiffness and weakness in the muscles surrounding the affected area, even after they should’ve healed.
- Your mobility is significantly impeded.
What Are the Common Risk Factors?
Some people get CRPS following an injury, from a severe stroke to a common sprained ankle. Others go their entire lives without ever experiencing or hearing about CRPS. We don’t entirely or fully understand why some people are more prone to CRPS than others, and if genes do play a role, we don’t know which ones are responsible for the development of CRPS. Age and sex do seem to play a role. As mentioned, women aged 40 are most likely to develop CRPS. Pre-existing nerve conditions can make CRPS much more likely, predominantly peripheral neuralgia caused by alcohol consumption or diabetes. Autoimmune disorders are also expected to co-occur with CRPS. In these cases, it’s the body’s antibodies that may be damaging your nerves.
How Is It Treated?
There are several different medical treatments, although all of them fall under the umbrella of pain management. A few treatment options include:
Most complex regional pain syndrome cases go away independently, given enough time and care. However, in very severe cases, chronic cases may require more extensive treatments, including short-term nerve blocks and nerve ablation or surgery. Ultimately, symptom reduction is essential here. A treatment plan must be individualized. Discuss your treatment options with your doctor or pain specialist and get case-specific help.