Calcium pyrophosphate dihydrate crystal deposition disease

A form of arthritis caused by calcium pyrophosphate dihydrate crystal deposition

Birefringence microscopy of pseudogout

Calcium pyrophosphate dihydrate crystal deposition disease (CPPD), also known as pseudogout, is a form of arthritis characterized by the deposition of calcium pyrophosphate dihydrate crystals in the joints. This condition can lead to joint inflammation and pain, similar to gout, but is caused by different types of crystals.

Pathophysiology

CPPD occurs when calcium pyrophosphate dihydrate crystals accumulate in the joint cartilage. These crystals can cause inflammation and damage to the joint, leading to symptoms similar to those of other forms of arthritis. The exact mechanism of crystal formation is not fully understood, but it is believed to involve an imbalance in the metabolism of calcium and phosphate.

Pseudogout crystals (calcium pyrophosphate dihydrate crystal)

Clinical Presentation

Patients with CPPD may present with sudden onset of joint pain, swelling, and redness, often affecting the knees, wrists, shoulders, ankles, or elbows. The symptoms can mimic those of gout, but unlike gout, CPPD is not caused by uric acid crystals.

Diagnosis

The diagnosis of CPPD is typically made through a combination of clinical evaluation and imaging studies. X-rays may show characteristic calcifications in the cartilage, known as chondrocalcinosis. Joint fluid analysis can reveal the presence of calcium pyrophosphate dihydrate crystals, which can be identified by their rhomboid shape and positive birefringence under polarized light microscopy.

Calcium pyrophosphate

Treatment

Treatment of CPPD focuses on relieving symptoms and preventing further joint damage. Nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly used to reduce pain and inflammation. In some cases, colchicine or corticosteroids may be prescribed. Joint aspiration can also provide relief by removing excess fluid and crystals from the joint.

Prognosis

The prognosis for patients with CPPD varies. Some individuals may experience only occasional flare-ups, while others may develop chronic arthritis with persistent symptoms. Early diagnosis and management are crucial to prevent joint damage and maintain quality of life.

Chondrocalcinosis

Related Conditions

CPPD is often associated with other metabolic disorders, such as hyperparathyroidism, hemochromatosis, and hypomagnesemia. It is important to evaluate patients for these conditions, as their management may influence the course of CPPD.

Related pages

• Gout
• Arthritis
• Chondrocalcinosis

Pseudogout - high magnification