Calcium Pyrophosphate Deposition (CPPD)
Calcium pyrophosphate deposition (CPPD), also known as “pseudogout,” is a type of arthritis characterized by the formation of calcium pyrophosphate (CPP) crystals, which settle in joint cartilage and trigger inflammation. CPPD is more common in people over 60 but can occur earlier. The exact cause of CPP crystal formation remains unknown, but several risk factors have been identified, including Gitelman syndrome (inherited kidney disorder), hemochromatosis (inherited condition leading to excess iron), familial hypocalciuric hypercalcemia (inherited disorder causing high calcium levels), hypophosphatasia (inherited disorder affecting bone and teeth mineralization), low magnesium levels, and abnormalities of the parathyroid gland. Additionally, CPP crystals are often found in the joints of individuals with osteoarthritis or gout.
What Are the Signs/Symptoms?
CPPD symptoms include severe joint pain, warmth, and swelling. While the knees are the most commonly affected joints, CPPD can also involve other joints. If left untreated, it may lead to recurrent, painful attacks and chronic joint inflammation, potentially causing cartilage breakdown, disability, and persistent pain. A rheumatologist diagnoses CPPD based on symptoms and medical tests. In some cases, joint fluid analysis may be necessary to confirm the presence of CPP crystals. The most commonly used imaging techniques for visualizing CPP crystals in the joints are X-rays and musculoskeletal (MSK) ultrasound, while MRI appears to be less sensitive. Other imaging methods, such as Dual-Energy CT (DECT), are currently being studied for their effectiveness in detecting CPPD.
What Are Common Treatments?
There is currently no treatment available to dissolve CPP crystals. A typical attack may last between 7 to 14 days. During acute episodes, a rheumatology healthcare professional may drain fluid from the affected joint and administer a corticosteroid injection to reduce inflammation. Additional anti-inflammatory treatments, such as nonsteroidal anti-inflammatory drugs (NSAIDs), oral glucocorticoids, colchicine, and the interleukin-1 beta antagonist anakinra (Kineret), may be used alongside joint injections for symptom relief. For patients experiencing frequent attacks, prophylactic treatment may be beneficial. Colchicine, NSAIDs, or low-dose corticosteroids can be considered for prevention, but the appropriate approach should be discussed with a rheumatology healthcare professional based on individual needs.
Living with CPPD
Prompt diagnosis and treatment of CPPD may ease symptoms and prevent joint damage. See a rheumatology healthcare professional as soon as symptoms appear to rule out other possible causes and start treatment. Rheumatology healthcare professionals may refer some people with CPPD to physical and occupational therapists. These clinicians guide therapy to improve flexibility, ease joint pain and adapt movements for better function.
Updated February 2025 by Howard Yang, MD, RhMSUS, and reviewed by the American College of Rheumatology Committee on Communications and Marketing.
This information is provided for general education only. Individuals should consult a qualified health care provider for professional medical advice, diagnosis and treatment of a medical or health condition.