Pseudogout is a joint disease that can cause attacks of arthritis . Like with gout, crystals form in the joints. But in pseudogout, the crystals are not formed from uric acid.
Calcium pyrophosphate dihydrate deposition disease; CPPD disease
Causes, incidence, and risk factors:
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:
Because the symptoms are similar, pseudogout can be misdiagnosed as:
- Attacks of joint pain and fluid buildup in the joint, leading to joint swelling
- Chronic (long-term) arthritis
There are no symptoms between attacks.
Signs and tests:
- An examination of joint fluid shows white blood cells and calcium pyrophosphate crystals.
Joint x-rays may show joint damage and calcium deposits in joint spaces.
Carefully testing crystals found in the joints can help the doctor diagnose the condition. Because most conditions involving joint pain are treated with the same medicines (such as steroids and nonsteroidal anti-inflammatory drugs), you may still get the right treatment even if your diagnosis was incorrect at first.
Treatment may involve removing fluid to relieve pressure in the joint. A needle is placed into the joint and fluid is removed (aspirated).
Steroid injections may help treat severely swollen joints. Oral steroids are sometimes used when many joints are swollen.
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.
Calling your health care provider:
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.
References: Goldman L, Ausiello DA. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007.