Pseudogout

Overview

Pseudogout (SOO-doe-gout) is a type of arthritis that causes sudden and painful swelling in one or more of the joints. Episodes can last for days or weeks.

The medical term for pseudogout is calcium pyrophosphate deposition disease, often shortened to CPPD. But the condition commonly is called pseudogout because its symptoms are similar to those of gout. In both conditions, crystals deposit in the joints, but the types of crystals differ. Pseudogout is caused by calcium crystals while uric acid crystals cause gout.

It isn't clear why crystals form in joints and cause pseudogout, but the risk increases with age. Treatment options are available to help relieve pain and lessen inflammation.

Symptoms

Pseudogout typically affects the knees. Less often, it affects the wrists and ankles. It also may affect large joints, such as the hips. And pseudogout can affect small joints, such as in the fingers and toes. When a pseudogout attack occurs, the affected joints typically are:

• Swollen.
• Warm.
• Very painful.
• Difficult to move or to put weight on.

When to see a doctor

Seek medical care if you have sudden, intense joint pain and swelling.

Causes

Pseudogout has been linked to calcium pyrophosphate dihydrate crystals forming in the joints. These crystals become more common as people age, appearing on X-rays in nearly half of those over 85. The medical term for this is chondrocalcinosis. But most people who have these crystal deposits never develop symptoms of pseudogout. It's not clear why some people develop symptoms while others don't.

Risk factors

Factors that can increase the risk of pseudogout include:

• Age. The likelihood of pseudogout rises with age.
• Joint injury or surgery. Trauma to a joint, such as a serious injury or surgery, increases the risk of pseudogout in that joint.
• Family history. Some families have a higher risk of developing pseudogout, which suggests that genetics may play a role. This inherited tendency also may cause the condition to appear at a younger age. And a genetic condition called hemochromatosis causes the body to store too much iron, which can increase the risk of developing pseudogout.
• Mineral imbalances. The risk of pseudogout is higher for people who have too much iron in their blood, called hemochromatosis, or too little magnesium, called hypomagnesemia.
• Other medical conditions. Pseudogout also has been linked to an underactive thyroid gland or an overactive parathyroid gland.

Complications

The crystal deposits associated with pseudogout can damage joints, causing symptoms similar to those of osteoarthritis or rheumatoid arthritis.