CRPS may be severe, long lasting

DEAR DOCTOR K: My daughter was diagnosed with complex regional pain syndrome after a car accident. She’s in a lot of pain. What do you recommend?

DEAR READER: CRPS is a long-lasting condition that causes severe, constant, burning pain in the affected arm or leg. As in your daughter’s case, it usually starts after an injury or other trauma. In the last 20 years we’ve learned a lot about what goes wrong in the body with this condition, and about good treatments for it. But we still don’t have a fundamental understanding of it, or perfect treatments.

What we know is that CRPS is triggered by nerve damage in injured tissue. The damaged nerves become overly sensitive. Pain signals become more painful. The brain experiences common stimuli, such as light touch, as being painful.

The earlier treatment begins, the better. Maintaining movement is an important goal. This is usually accomplished with physical therapy and, eventually, a regular exercise program.

Medications that may help manage pain include:

• Nonsteroidal anti-inflammatory drugs (NSAIDs) and other pain relievers.

• Capsaicin, a cream or ointment thought to interrupt or “distract” pain signals.

• Certain antidepressants and anticonvulsants.

• Certain blood pressure medications.

• Bisphosphonates, medications that reduce bone loss.

• Trigger-point injections of an anti-inflammatory medicine and a long-acting local anesthetic.

• A transcutaneous electrical nerve stimulator unit may help to relieve pain. Biofeedback can help to control pain, blood flow and skin temperature.

For severe pain that does not respond to other treatment, a nerve block may help.

A few newer treatments are available for severe cases. One entails implanting a device to stimulate the spinal cord or nearby nerves. The other involves injecting a drug that relaxes blood vessels into the space near the spinal cord. These treatments do not always work and may cause complications. But if nothing else has helped, the benefits may exceed the risks.