Autoimmunity Linked To Complex Regional Pain Syndrome
Complex Regional Pain Syndrome is a rare complication of common problems. The most common problems that can lead to CRPS are a bone fractures but other minor injuries can also trigger can avalanche of pain including a needle stick (this fact scares the Red Cross). How can such small incidents turn into such huge mountains of pain? Many facts about CRPS puzzle doctors, like the fact that some people seem to have total-body involvement or the fact that asthma is associated with CRPS. Well a new piece of this puzzle is falling into place: autoimmunity.
Some scientists are now convinced that for a subtype of CRPS, the body seems to be attacking itself. Autoimmunity means that the body’s own defensive system turns on itself. In a certain of subset of people with CRPS, the nerves are under attack.
Autoantibodies, a protein that targets “self” tissues, have been found to be attacking the peripheral small fiber nerves in those with some types of nerve pain. Upwards of 30-40 percent of those with CRPS have these autoantibodies. Those who have CRPS following minimal or actually no traumatic injury are more likely to have an autoimmune component of the painful condition. With this growing body of medical evidence, researchers hope to offer new solutions to those with CRPS and/or a possible cure.
For those with early stages of CRPS, oral corticosteroids have been shown to be effective at aborting the pain cycle. These steroids block the immune system from revving up. For those with later stages of CRPS, immunotherapy may hold some promise. Recently, scientists have shown that the inflammatory mechanism in neuropathies is responsive to immunotherapy. The microvasculitis (small blood vessel inflammation) and degeneration of the nerve may be reversible. Furthermore, intravenous immunoglobulin may be beneficial in select patients with CRPS.
Immunoglubulin therapy is another a way to block the immune system. The key to immunotherapy for CRPS might be patient selection because not all forms of CRPS have an autoimmunity link. For some, immunotherapy offers some hope. However, because many scientists are skeptical about the effectiveness of immunotherapy for CRPS, this type of therapy is still very experimental.
For now, CRPS remains to be a perplexing puzzle that seems to defy what is actually known about the human body; yet, at the same time, it stretches the imagination of scientists around the world. One additional clue that autoimmunity might be an important link is the fact that the elderly who are known to have weak immune systems rarely develop CRPS. If that is the case, should not CRPS get better with age? Not necessarily, because the irreversible nerve damage might already be done. Still, our best hope for dealing with CRPS is to find ways to prevent it from occurring by protecting the nerves with things like vitamins and by keeping the nerves healthy with good lifestyle habits.
Christina Lasich, M.D., wrote about chronic pain and osteoarthritis for HealthCentral. She is physiatrist in Grass Valley, California. She specializes in pain management and spine rehabilitation.