Pseudogout

Deposition of calcium pyrophosphate in the joints and soft tissues leads to inflammation

Aetiology

  • Most common in the elderly
    • Chondrocalcinosis increases with age
      • Chondrocalcinosis: calcium pyrophosphate deposition occurs in cartilage and other soft tissues in the absence of acute inflammation
      • Both pseudogout and chondrocalcinosis come under the umbrella of Calcium Pyrophosphate Deposition disease (CPPD)
    • Related to osteoarthritis - calcium deposition can occur in some cases of OA
  • Affects fibrocartilage - knees, wrists, ankles

Other risk factors

  • Hyperparathyroidism
  • Familial hypocalciuric hypercalcaemia
  • Haemochromatosis
  • Wilson's disease
  • Haemosiderosis
  • Hypophosphatasia
  • Hypomagnesemia
  • Hypothryoidism
  • Gout
  • Neuropathic joints
  • Amyloiosis
  • Trauma

Clinical presentation

  • Monoarthritis - swollen, painful, warm joint
  • Knee most commonly affected

Investigations

Aspiration of synovial fluid

  • Polarised microscopy - calcium pyrophosphate crystals are envelope shaped, mild positively birefringent

Bloods

  • Marked rise in inflammatory markers

Management

  • Treat acute episodes appropriately - NSAIDs, colchicine, steroids, rehydration
  • No prophylactic management