Alternative Names: Calcium pyrophosphate deposition disease; CPPD

Causes, incidence, and risk factors:

Pseudogout is caused by the collection of calcium pyrophosphate crystals in joints. There may be attacks of joint swelling and pain in the knees, wrists, ankles, and other joints.

This condition primarily affects the elderly and usually has no known cause. However, it can sometimes affect younger patients who have conditions such as acromegaly, ochronosis, thyroid disease, hemochromatosis, Wilson disease, and parathyroid disease, which are known to increase risk.

Pseudogout can be initially be misdiagnosed as gouty arthritis, rheumatoid arthritis, or osteoarthritis because the symptoms are similar to those of these conditions.

Careful workup, with analysis of crystals found in joints, should ultimately lead to the correct diagnosis. Fortunately, because most conditions involving joint pain are treated by the same medicines, early misdiagnosis does not necessarily result in inappropriate treatment. Such treatment often includes steroids and nonsteroidal anti-inflammatory drugs (NSAIDs),

Symptoms:

• Attacks of joint pain and fluid accumulation in the joint, leading to joint swelling
• No symptoms between attacks
• Chronic (long-term) arthritis

Signs and tests:

• An examination of joint fluid would show white blood cells and calcium pyrophosphate crystals.
• Joint x-rays may show joint damage, calcification of cartilage, and calcium deposits in joint spaces.

Treatment:

Treatment may involve joint aspiration to relieve pressure within the joint caused by fluid buildup. A needle is placed into the joint and fluid is removed (aspirated).

Steroid injections may be helpful to treat severely inflamed joints. A course of oral steroids is sometimes used when multiple joints are inflamed.

Nonsteroidal anti-inflammatory medications (NSAIDS) may help ease painful attacks. Colchicine may be useful in some people.

Support Groups:

Expectations (prognosis):

The probable outcome is good with treatment.

Complications:

Permanent joint damage can occur without treatment.

Calling your health care provider:

Call for an appointment with your health care provider if you have attacks of joint swelling and joint pain.

Prevention:

There is no known way to prevent this disorder. However, treatment of a known predisposing condition may reduce the severity of pseudogout and may in effect prevent it from developing in unaffected patients.