Pseudogout, also known as calcium pyrophosphate deposition (CPPD) disease, is a type of arthritis that causes spontaneous, painful swelling in your joints. It occurs when crystals form in the synovial fluid (the fluid that lubricates the joints). This causes inflammation and pain. 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. It’s more common in older adults. While you can’t prevent the disease, you can find treatments to reduce the inflammation and relieve the pain.
Pseudogout occurs when calcium pyrophosphate crystals form 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.
Researchers don't fully understand why crystals form. The chance of them forming likely 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:
- bouts of joint pain
- swelling of the affected joint
- fluid buildup around the joint
- chronic arthritis
If your doctor thinks you have pseudogout, they may recommend the following tests:
- an analysis of joint fluid to look for calcium pyrophosphate crystals
- X-rays of the joints to check for any damage to the joint, calcification (calcium buildup) of the cartilage, and deposits of calcium in the joint cavities
Looking at the crystals found in the joint cavities helps your doctor make a diagnosis. This condition shares symptoms with other problems, so sometimes it may 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 drain the synovial fluid from the joint to relieve the pressure within the joint and reduce inflammation.
To help with acute attacks, your doctor may prescribe nonsteroidal anti-inflammatory drugs (NSAIDs) to reduce the swelling and relieve the pain.
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 wearing out, your doctor may recommend surgery to repair or replace them. There is currently no treatment available to get rid of the crystal deposits.
Outlook and Complications
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 (growths that stick out on the bones due to excessive friction), cysts, or loss of cartilage.
There is no way to prevent pseudogout. Treating the underlying condition(s) that cause it (hypothyroidism, magnesium deficiency, etc.) may slow its development and lessen the severity of symptoms.