Arthritis and Pseudogout
Pseudogout is a form of arthritis that causes pain, stiffness, tenderness, redness, warmth, and swelling in some joints. It can affect one or several joints at once.
Pseudogout commonly affects the knee or wrist. Less often, it can involve the hips, shoulders, elbows, finger joints, toes, or ankles.
What Causes Pseudogout?
Pseudogout results from the abnormal formation of calcium pyrophosphate (CPP) crystals in the cartilage (cushioning material between the bones), which is later followed by the release of crystals into the joint fluid. When CPP crystals are released into the joint, they can cause a sudden attack of arthritis, similar to gout.
The cause of abnormal deposits of CPP crystals in cartilage is unknown. They may form due to abnormal cells in the cartilage, or they may be produced as the result of another disease that damages cartilage. CPP crystals may be released from cartilage during a sudden illness, joint injury, or surgery. The abnormal formation of CPP crystals also may be a hereditary trait.
What Are the Symptoms of Pseudogout?
The symptoms of pseudogout are similar to those of other diseases, especially gout, which is caused by a buildup of uric acid. They also mimic those of rheumatoid arthritis or osteoarthritis. Symptoms include:
- Sudden, intense joint pain
- Swollen joint that's warm to the touch
- Red or purple skin around the joint
- Severe tenderness around the joint (even the slightest touch or pressure may bring extreme pain)
Less often, pseudogout may cause persistent swelling, warmth, and pain in several joints and can even mimic rheumatoid arthritis.
Most symptoms of pseudogout go away within five to 12 days, even without treatment.
Who Gets Pseudogout?
Pseudogout affects both men and women. Like gout, pseudogout occurs more frequently in people over age 60. People who have a thyroid condition, kidney failure, or disorders that affect calcium, phosphate, or iron metabolism are at increased risk for pseudogout.
Pseudogout also is commonly seen in people who have osteoarthritis. "Attacks" of osteoarthritis associated with pain, swelling, and redness of the joint may in fact be due to pseudogout.
It is unusual for young people to develop pseudogout.