Pseudogout 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 leads to inflammation and pain.
This condition most often affects the knees, but it can affect other joints as well. It’s more common in adults over the age of 60.
Pseudogout is also known as calcium pyrophosphate deposition (CPPD) disease.
Pseudogout and gout are both types of arthritis, and they’re both caused by the accumulation of crystals in the joints.
While pseudogout is caused by calcium pyrophosphate crystals, gout is caused by urate (uric acid) crystals.
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 the crystals form. The chance of them forming likely increases with age. Crystals form in about half of people over the age of 85, according to the Arthritis Foundation. However, many of them don’t have pseudogout.
Pseudogout can often run in families, so many medical professionals believe it to be a genetic condition. Other contributing factors may include:
- hypothyroidism, or an underactive thyroid
- hyperparathyroidism, or an overactive parathyroid gland
- excess iron in the blood
- hypercalcemia, or too much calcium in the blood
- magnesium deficiency
Pseudogout most often affects the knees, but it also affects the ankles, wrists, and elbows.
General symptoms may include:
- bouts of joint pain
- swelling of the affected joint
- fluid buildup around the joint
- chronic inflammation
If your doctor thinks you have pseudogout, they may recommend the following tests:
- an analysis of joint fluid by removing the fluid from the joint (arthrocentesis) 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
- MRI or CT scans to look for areas of calcium buildup
- ultrasound also to look for areas of calcium buildup
Looking at the crystals found in the joint cavities helps your doctor make a diagnosis.
This condition shares symptoms with other conditions, so it may sometimes be misdiagnosed as:
- osteoarthritis (OA), a degenerative joint disease caused by loss of cartilage
- rheumatoid arthritis (RA), a long-term inflammatory disorder that may affect several organs and tissues
- gout, which causes painful inflammation of the toes and feet commonly but can affect other joints
Pseudogout can sometimes be associated with other illnesses, such as:
- the thyroid disorders hypothyroidism and hyperparathyroidism
- hemophilia, a hereditary bleeding disorder that prevents the blood from clotting normally
- ochronosis, a condition that causes a dark pigment to deposit in the cartilage and other connective tissues
- amyloidosis, a buildup of an abnormal protein in the tissues
- hemochromatosis, an abnormally high level of iron in the blood
There’s currently no treatment available to get rid of the crystal deposits.
Draining the fluid
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’re 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 medications used to treat pseudogout include:
- hydroxychloroquine (Plaquenil, Quineprox)
- methotrexate (Rheumatrex, Trexall)
If your joints are wearing out, your doctor may recommend surgery to repair or replace them.
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 cysts or bone spurs, which are growths that stick out on the bones.
Pseudogout may also result in loss of cartilage.
The symptoms of pseudogout can last anywhere from a few days to several weeks. Most people are able to manage the symptoms very well with treatment.
Complementary home remedies such as cold therapy may bring additional relief.
While you can’t prevent the disease, you can find treatments to reduce the inflammation and relieve the pain. Treating the underlying condition that causes pseudogout may slow its development and lessen the severity of symptoms.