Recently adopted diagnostic criteria can help primary care physicians assess patients for this rare and painful condition.
Joshua P. Prager, MD, MS
Some physicians may see vascular disease. Others may suspect a mental disorder. The majority, however, may simply believe the patient is wildly exaggerating the intensity and severity of their pain. How else can one explain a patient who twists an ankle and complains of agonizing pain months later? Whatever the specific misdiagnosis, nonspecialists often struggle to spot Complex Regional Pain Syndrome (formerly known as Reflex Sympathetic Dystrophy, or RSD), a rare but excruciating chronic pain condition.
In patients with CRPS, “the amount of pain will always seem wildly out of proportion to the injury that set it in motion. That’s the essence of the condition and a key to making the diagnosis. In some cases, the triggering event is so minor that the patient has no recollection of it,” says Norman Harden, MD, Addison Chair in Pain Studies at Northwestern University and Director of the Rehabilitation Institute of Chicago’s Center for Pain Studies.
Harden, who helped develop the CRPS diagnosis system recently endorsed by the International Association for the Study of Pain (http://bit.ly/HPwKQt), believes that any doctor can learn to spot the condition. “CRPS is not a hard diagnosis to make using the IASP criteria, except in borderline cases,” Harden says. “A full-blown case presents vivid symptoms. See it once and you’ll never forget it.”
CRPS occurs when an injury triggers an exaggerated response in the periphery and the central nervous system that becomes self-perpetuating. The underlying cause remains in doubt. Researchers once suspected that it correlated strongly with depression, but subsequent work suggests an organic and perhaps genetic cause.
The diagnosis guidelines that Harden helped develop identify four categories of symptom:
Physicians who observe signs from at least two of these categories and document symptoms from at least three categories should make the CRPS diagnosis; there is currently no validated objective test or scan that confirms the diagnosis.
“When in doubt, physicians should err on the side of ‘over-diagnosing’ rather than risk missing a case,” says Bennet E. Davis, MD, cofounder of the Integrative Pain Center of Arizona. “Mistakenly sending someone to a pain specialist isn’t that serious. Delaying proper care for this condition is really serious.”
After making the CRPS diagnosis, if dealing with a very mild case, a non-specialist might try a few weeks of treatment that combines pain medication with physical therapy. However, if the condition does not improve quickly, the patient should be referred to a specialist.
"Treatment for CRPS is a complex, multidisciplinary undertaking that combines medication, exercise, and often psychological therapy—all customized for each individual patient."
—Joshua P. Prager, MD, MS, Director, Center for the Rehabilitation Pain Syndromes at UCLA Medical Plaza
Indeed, in the vast majority of cases, patients should be referred to specialists immediately after diagnosis. “Treatment for CRPS is a complex, multidisciplinary undertaking that combines medication, exercise, and often psychological therapy—all customized for each individual patient,” says Joshua P. Prager, MD, MS, Director, Center for the Rehabilitation Pain Syndromes at UCLA Medical Plaza. “Trying to treat CRPS as a non-specialist is about as wise as trying to treat cancer as a non-specialist.”
CRPS is rare enough that most general practitioners may see only one or two cases per year. Orthopedic and spine surgeons, on the other hand, will probably see several CRPS patients each year because the trauma of surgery can be enough to trigger the condition. Prager says that surgeons shouldn’t hesitate to diagnose CRPS and send patients to specialists because they fear malpractice lawsuits. The trauma associated with even perfect surgery can trigger CRPS, so it is generally no indication of surgeon error.