Your neighbor, Dorothy Roberts, age 64, comes out to pick up her mail, and you notice she’s limping. You ask what happened, and she says she got up last night to make sure her doors were locked and accidentally walked into a chair, hitting her foot hard against the chair leg. She’s having a lot of pain. The ibuprofen she took hasn’t helped much, so she’s going to see her physician, Dr. Wall, today.
Severe pain persists
When you see Dorothy later in the week and ask her about her pain, she says that the X-rays didn’t show any broken bones but the pain is still severe. She rates the pain at 7/10 and says it not only aches but burns. She tried ice on her foot with little effect. She can’t wear a shoe, so she’s wearing a bedroom slipper.
Dr. Wall gave her Tylenol #3 (acetaminophen with codeine) to take several times a day. Though she’s taking it regularly, it reduces the pain by only 50%. Her foot is becoming sensitive to touch and seems to be swollen and cool most of the time. Elevating her foot eases the pain. She wakes up frequently at night because of the pain.
Several months later, you see Dorothy using crutches to walk. She says she’s going to physical therapy, where she walks and bears weight. When you ask if Dr. Wall has identified the problem, she says that despite many tests and X-rays, he doesn’t know what’s causing the pain. She has stopped talking to him about it because she’s embarrassed to say just how much it still hurts.
Opioid needed
She has complained so much that Dr. Wall prescribed Vicodin (hydrocodone and acetaminophen), but he also told her he was getting concerned about her continuing need for an opioid and the amount of acetaminophen she’s taking. Dorothy says she’s getting discouraged about the continuing pain and feels depressed. Dr. Wall has suggested she go to a psychologist for help and made a referral to a pain specialist.
Dorothy confides, “I know this pain isn’t just in my head. It hurts so bad. I can’t keep going on this way. I’ll go to anyone I think can help. I haven’t had a good night’s sleep since I hurt my foot. My foot is cold all the time. I can’t stand to have anything touch it. Just a light touch sends the pain all through my foot. And I keep thinking that I did this all to myself. What if no one can help me?”
Appointment with a pain specialist
You encourage Dorothy to continue reporting her pain and to go to the pain specialist. You also advise her that having a positive outlook can help her regain some control over the pain and the changes in her life.
When Dorothy sees the pain specialist, he examines her foot and reviews her X-rays. He notes that the foot is edematous, looks a little darker than the other one, has a hypersensitive response to normal touch, and feels cool to touch.
Time for your analysis
Considering all the evidence in this case history, what’s your opinion? What’s the cause of Dorothy’s pain? After you make a decision, read on to see the pain specialist’s diagnosis.
Understanding the diagnosis
The pain specialist diagnosed Dorothy with complex regional pain syndrome (CRPS).
This condition may result from surgery, a fracture, or a simple injury. The mechanism of pain production is thought to be either a hypersensitivity to catecholamines by alpha-adrenergic receptors or a functional interaction between sympathetic and sensory neurons.
Typically, CRPS affects a hand or foot. Not using the affected limb probably increases the loss of functionality. The pain usually spreads to include more than the injury site. Rarely, pain develops in the opposite hand or foot—a phenomenon called mirror-like spread or mirror symptoms.
Dorothy’s signs and symptoms are typical: increased levels of pain to touch (called allodynia), thermal changes, edema, and skin color changes. Other signs and symptoms include sudomotor abnormalities and changes to the skin, hair, and nails, including hair loss in the affected area and nails that grow long, thicken, and start to curve because they are so painful to cut.
Protecting the injured hand or foot and not using it, as Dorothy has done, will eventually lead to muscle weakness, spasms, muscle wasting, contractures, and pathological bone fractures.
Treating CRPS
The best treatment is early detection and aggressive pain management. When a patient with a relatively minor injury has the signs and symptoms described above, suspect CRPS. The condition is easy to treat during the first 3 months and very difficult to treat after that.
Drugs used to treat CRPS include gabapentin, tricyclic antidepressants (TCAs), nonsteroidal anti-inflammatory drugs, opioids, and clonidine. A sympathetic nerve block before physical therapy can help a patient tolerate the activity. And topical applications, such as a lidocaine patch (Lidoderm) or capsaicin, also may help. Spinal cord stimulation is an option after other therapies fail.
Dorothy’s therapy
After seeing the pain specialist for 6 months, Dorothy regained some of her normal function. She seems brighter and walks better.
The pain specialist has done some local anesthetic blocks, so she can work on making her foot less sensitive to pain and improve her ability to put pressure on it. And she takes several drugs, including methadone and a TCA at night to ease her neuropathic pain and help her sleep. Occasionally, she needs Vicodin for breakthrough pain when she’s too active.
She saw a psychologist who taught her to do relaxation exercises at night before she tries to sleep. She also wears a Lidoderm patch at night because it numbs the painful area. Dorothy understands that her foot will never be the same again. But she’s grateful that the cause of her pain has been properly diagnosed and that her treatment allows her to perform her daily activities with minimal pain.
Selected references
Edwards R. Individual differences in endogenous pain modulation as a risk factor for chronic pain. Neurology. 2005;65(3):437-443.
Flor H, Kalso E, Dostrovsky J, eds. Proceedings of the 11th World Congress on Pain. IASP Press: Seattle; 2006.
Forss N, Kirveskari E, Gockel M. Mirror-like spread of chronic pain. Neurology. 2005;65(5):748-750.
Galer B, Dworkin R. Neuropathic Pain. Minneapolis, Minn: McGraw-Hill; 2000.
Harden N. Pharmacotherapy of complex regional pain syndrome. Am J Phys Med Rehabil. 2005;84(3):S17-S28.
Yvonne D’Arcy, MS, CRNP, CNS, is a Pain Management and Palliative Care Nurse Practitioner at Suburban Hospital in Bethesda, Maryland.
