• Definition

    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.

    Alternative Names

    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:

    • 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