Pseudogout / CPPD Arthritis

Understanding Pseudogout / CPPD Arthritis

What Is Ankylosing Spondylitis?

Pseudogout, also known as Calcium Pyrophosphate Deposition (CPPD) arthritis, is a type of inflammatory arthritis caused by the deposition of calcium pyrophosphate dihydrate crystals in the joints. It can mimic gout, osteoarthritis, or rheumatoid arthritis, but the underlying cause is different.

Common Symptoms:

  • Sudden, painful swelling in one or more joints (often the knee, wrist, or ankle)
  • Warm, red, tender joint-can mimic gout or infection
  • Can also present as chronic joint pain and stiffness, like osteoarthritis

What Causes CPPD?

CPPD occurs when calcium pyrophosphate crystals accumulate in joint cartilage and surrounding tissues. The crystals can trigger an inflammatory reaction when they shed into the joint space.

Risk Factors

  • Age: Most common in people over 60
  • Joint trauma or surgery
  • Genetics: Family history may increase risk
  • Metabolic conditions: Hyperparathyroidism, Hemochromatosis, Hypomagnesemia, Hypophosphatasia

Diagnosis

  • Joint aspiration (arthrocentesis): Synovial fluid is examined under a microscope
  • Shows rhomboid-shaped, weakly positively birefringent crystals
  • X-rays may show chondrocalcinosis (calcification of cartilage)

Treatment

There’s no cure, but flare-ups and chronic symptoms can be managed:

  • NSAIDs (e.g., ibuprofen, naproxen)
  • Colchicine (acute and prophylactic use)
  • Corticosteroids (oral or intra-articular)
  • Joint aspiration to relieve pressure and inflammation

Important Notes

Unlike gout (which is due to uric acid crystals), pseudogout involves calcium pyrophosphate.

Can be misdiagnosed as other joint disorders, so crystal analysis is key.