Pseudogout (SOO-doe-gout) is a form of arthritis characterized by sudden, painful swelling in one or more of the joints. Episodes can last for days or weeks.
Pseudogout is formally known as calcium pyrophosphate deposition disease or CPPD. But the condition is commonly called pseudogout because of its similarity to gout. In both pseudogout and gout, crystal deposits form within a joint, although the type of crystal differs for each condition.
It isn't clear why crystals form in joints and cause pseudogout, but the risk increases with age. Treatments can help relieve pain and reduce inflammation.
Pseudogout most commonly affects the knees. Less often, it affects the wrists and ankles. When a pseudogout attack occurs, the affected joints are usually:
Seek medical attention if you have sudden, intense joint pain and swelling.
Pseudogout has been linked to the presence of calcium pyrophosphate dihydrate crystals within the affected joint. These crystals become more numerous as people age, appearing in nearly half the population older than age 85. But most people who have these crystal deposits never develop pseudogout. It's not clear why some people have symptoms and others don't.
Factors that can increase your risk of pseudogout include:
The crystal deposits associated with pseudogout can also cause joint damage, which can mimic the signs and symptoms of osteoarthritis or rheumatoid arthritis.
Pseudogout symptoms can mimic those of gout and other types of arthritis, so lab and imaging tests are usually necessary to confirm a diagnosis.
Blood tests can check for problems with your thyroid and parathyroid glands, as well as for mineral imbalances that have been linked to pseudogout.
To test the fluid in your affected joint for the presence of crystals, your health care provider may withdraw a sample of the fluid with a needle. This procedure is called joint aspiration (arthrocentesis).
X-rays of your affected joint often can reveal joint damage and crystal deposits in the joint's cartilage.
There's no cure for pseudogout, but a combination of treatments can help relieve pain and improve the joint's function.
If over-the-counter pain relievers aren't enough, your health care provider may suggest:
Removing some of the joint fluid can relieve pain and pressure in an affected joint. A needle is used to remove the fluid. The process also helps remove some of the crystals from the joint. The joint is then injected with a numbing medication and a corticosteroid to decrease inflammation.
Home treatments may be useful during pseudogout flare-ups. Examples include:
You'll probably first see your family health care provider. After an initial examination, your provider may refer you to a specialist in the diagnosis and treatment of arthritis and other inflammatory joint conditions (rheumatologist).
Here's some information to help you get ready for your appointment.
Before your appointment, you may want to write a list of answers to the following questions:
A health care provider who sees you for symptoms common to pseudogout may ask a number of questions. You might be asked: