Pseudogout, also known as calcium pyrophosphate deposition (CPPD) disease, is a type of arthritis that causes spontaneous, painful swelling in your joints. This condition most commonly affects the knees, but it can also affect the ankles, elbows, and wrists. The symptoms can last anywhere from a few days to several weeks.
Pseudogout occurs when crystals form in the synovial fluid (the fluid that lubricates the joints) and then cause inflammation and pain. It is not known why crystals form in the synovial fluid. Although the disease cannot be prevented, treatments are available to reduce the inflammation and to relieve the pain.
Pseudogout is more common in older adults.
Pseudogout is caused by the formation of calcium pyrophosphate crystals in the synovial fluid in the joints. Crystals can also deposit in the cartilage, where they can cause damage. Buildup of crystal in the joint fluid results in swollen joints and acute pain.
It is not fully understood why crystals form, although the likelihood of it happening increases with age. Pseudogout can often run in families, so many medical professionals believe it to be a genetic condition. Other contributing factors may include:
- hypothyroidism—underactive thyroid
- excess iron
- magnesium deficiency
- overactive parathyroid gland
- hypercalcemia—too much calcium in the blood
Pseudogout most often affects the knees, but also affects ankles, wrists, and elbows. General symptoms may include:
- periodic episodes of joint pain
- swelling of the affected joint
- fluid buildup around the joint
- chronic arthritis
If your doctor suspects that you are suffering from pseudogout, he or she may recommend the following tests:
- an analysis of joint fluid to detect the presence of calcium pyrophosphate crystals
- X-rays of the joints to reveal any damage to the joint, calcification of the cartilage, and deposits of calcium in the joint cavities
Analysis of crystals found in the joint cavities will help your doctor to diagnose the condition. Because of similar symptoms, pseudogout may sometimes be misdiagnosed as:
- osteoarthritis—a degenerative joint disease caused by loss of cartilage
- rheumatoid arthritis—a long-term inflammatory disorder that may affect several organs and tissues
- gouty arthritis—a disorder causing painful inflammation of the toes and feet
Pseudogout can sometimes be associated with other illnesses, such as:
- hemophilia—a hereditary bleeding disorder that prevents the blood from clotting normally
- ochronosis—a condition causing the deposit of a dark pigment in the cartilage and other connective tissues
- amyloidosis—an abnormal buildup of protein in the tissues
- hypothyroidism—underactive thyroid glands
- hyperparathyroidism—an excessive amount of parathyroid hormone in the blood
- hemochromatosis—an abnormally high level of iron in the blood
Your doctor may wish to drain the synovial fluid from the joint to relieve the pressure within the joint and to reduce inflammation.
If you are suffering from acute attacks of pseudogout, your doctor may prescribe nonsteroidal anti-inflammatory drugs, (NSAIDs), to reduce the swelling and relieve the pain. There is no treatment available to get rid of the crystal deposits. You may not be able to take NSAIDs if:
- you are taking blood-thinning medication, such as warfarin (Coumadin)
- you have poor kidney function
- you have a history of stomach ulcers
To help reduce the risk of additional flare-ups, your doctor may prescribe low doses of colchicine (Colcrys) or NSAIDs.
Other medication treatments include:
- hydroxychloroquine (Plaquenil, Quineprox)
- methotrexate (Rheumatrex, Trexall)
- interleukin 1 beta-antagonist (Anakinra)
If your joints are degenerating, your doctor may recommend surgery to repair or replace them.
Most people are able to manage the symptoms very well with treatment.
In some cases, the crystal deposits in the synovial fluid can lead to permanent joint damage. Joints that have been affected by pseudogout can eventually develop bone spurs (protruding growths occurring on the bones due to excessive friction), cysts, or loss of cartilage.
There is no way to prevent pseudogout. However, treating the underlying condition(s) that caused the pseudogout (hypothyroidism, magnesium deficiency, etc.) may slow its development and lessen the severity of symptoms.