Pseudogout is a joint disease that can cause attacks of arthritis. Like gout, the condition involves the formation of crystals in the joints. But in pseudogout, the crystals are formed from a salt instead of uric acid.

Pseudogout is caused by the collection of salt called calcium pyrophosphate dihydrate (CPPD). The buildup of this salt forms crystals in the joints. This leads to attacks of joint swelling and pain in the knees, wrists, ankles, and other joints.

Among older adults, pseudogout is a common cause of sudden (acute) arthritis in one joint.

Pseudogout mainly affects the elderly. However, it can sometimes affect younger patients who have conditions such as:

• Acromegaly
• Hemochromatosis
• Ochronosis
• Parathyroid disease
• Thyroid disease
• Wilson disease

Because the symptoms are similar, pseudogout can be misdiagnosed as:

• Gouty arthritis (gout)
• Osteoarthritis
• Rheumatoid arthritis

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

• 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.

Careful testing and analysis of crystals found in joints can help the doctor diagnose the condition. Fortunately, because most conditions involving joint pain are treated by the same medicines (such as steroids and nonsteroidal anti-inflammatory drugs), an early mistaken diagnosis does not necessarily result in the wrong treatment.

Treatment may involve the removal of fluid to relieve pressure within the joint. 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.

Most people do well with treatment.

Permanent joint damage can occur without treatment.

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

There is no known way to prevent this disorder. However, treating other problems that may cause pseudogout may make the condition less severe, and may help prevent it from developing in patients who don't already have it.