Reflex sympathetic dystrophy syndrome (RSD) is a disorder that causes lasting pain, usually in an arm or leg, and it shows up after an injury, stroke, or even heart attack. But the severity of pain is typically worse than the original injury itself. Doctors don’t know exactly what causes it, but they are able to treat many cases.
The term reflex sympathetic dystrophy syndrome is actually not a name that doctors use anymore. It’s an older term used to describe one form of Complex Regional Pain Syndrome (CRPS). RSD is sometimes called Type I CRPS, and it’s caused by injury to tissue with no related nerve damage.
What Causes RSD?
Doctors think the pain caused by RSD comes from problems in your sympathetic nervous system. Your sympathetic nervous system controls blood flow movements that help regulate your heart rate and blood pressure.
When you get hurt, your sympathetic nervous system tells your blood vessels to get smaller so you don’t lose too much blood at your injury site. Later, it tells them to open back up so blood can get to damaged tissue and repair it.
When you have RSD, your sympathetic nervous system gets mixed signals. It turns on after an injury, but doesn’t turn back off. This causes a lot of pain and swelling at your injury site.
Sometimes, you can get RSD even if you haven’t had an injury, although it’s not as common.
RSD is a little more typical in women than in men. Children can get it, too, but usually it shows up between ages 30 and 60.
When you get RSD, your symptoms may show up slowly. You may have pain first, and then it may get worse over time. You may not realize your pain is abnormal at first.
The types of injuries that can cause RSD include:
It’s most common to get RSD in your arm, shoulder, leg, or hip. Usually the pain spreads beyond your injury site. In some cases, symptoms can spread to other parts of your body, too.
RSD can also affect your immune system. This can cause:
- Skin that’s warm to the touch around the injury
The pain you get with RSD is usually constant and severe. Many people describe RSD pain as:
Your skin may also feel sensitive when you do things that don’t normally hurt it, like taking a shower. Or it might hurt just to wear your clothes.
Other symptoms of RSD include:
Often, doctors don’t know your pain is being caused by RSD until you’ve had it for some time. When pain doesn’t go away, or is more severe than it should be for your type of injury, it can be the first clue that it could be RSD.
There’s no single test that can tell your doctor whether you have RSD. Instead, they’ll rely on a physical exam and your medical history information. There are also a few tests that can provide clues to see if you have certain signs of the condition. These include:
Bone scan. This test can detect if any of your bones are wearing away at the ends or whether there are issues with regular blood flow.
MRI. Your doctor might order an MRI to look inside your body, specifically at your tissues, for noticeable changes.
Sweat test. This test can tell your doctor if you sweat more on one side of your body than the other.
Thermography test. This sympathetic nervous system test checks to see if the temperature or blood flow is different at your injury site than in other parts of your body.
X-rays. These are typically ordered if your syndrome is in later stages to look for mineral loss in your bones.
Early detection is key in RSD treatment. The earlier you’re able to catch it, the better your treatment will work. Some cases of RSD don’t respond to treatment. RSD doesn’t have a cure, but it’s possible to recover from many of the symptoms.
Some of the medications your doctor may suggest include:
- Anesthetic creams like lidocaine
- Anti-inflammatory drugs, called NSAIDs
- Anti-seizure medications that may help treat pain
- Nasal spray that treats bone loss
- Nerve blocking injections
- Over-the-counter options like aspirin, ibuprofen, or naproxen for pain
Other treatments that are less frequently used because of their risk of side effects and the lack of evidence that they work as well include:
- Corticosteroids like methylprednisolone (Medrol) or prednisolone (AsmalPred Plus) to treat swelling
Opioids, such as fentanyl (Duragesic), hydrocodone (Hysingla ER, Zohydro ER), morphine (Arymo ER, Kadian,
Morphabond, MS Contin), and oxycodone
Other ways to treat symptoms include:
- Electrodes on your spinal cord that send small electric shocks to relieve pain
- Physical therapy to help you move around more easily and take away pain
- Psychotherapy that can teach you relaxation methods
- Splints to help with hand pain
If your pain doesn’t seem to be going away, even after treatment, your doctor may suggest a surgery called a sympathectomy. During this procedure, a surgeon removes certain nerves around your blood vessels to help improve your blood flow.