Gout / Pseudogout

Gout:

  • Negatively birefringent needle-shaped
  • Crystals of monosodium urate.
  • 40-50 yrs (men), > 60 yrs (women).
  • Any joint
  • Hallux MTP is involved in over 50% of first attacks.The white count on arthrocentesis can be v high.

    • Hydroxyapatite crystal arthritis:

    • Calcific periarthritis.
    • Shoulder.
    • Attacks precipitated by mild trauma or intercurrent infection.
    • Associated with scleroderma, hyperparathyroidism, dermatomyositis, inflammatory joint disease, and OA.

    Oxalate and lipid crystals can both cause a crystal arthropathy.

Pseudogout:

  • Positively birefringent rhomboidal crystals of
  • Calcium pyrophosphate dihydrate.
  • 60s to 70s, (F>M).
  • Most common cause of acute arthropathy in the elderly
  • Classically knees
  • Predisposing factors include haemochromatosis, hyperparathyroidism, hypomagnesaemia, hypophosphatasia, Wilson’s disease, gout and ochronosis.
  • Triggers include trauma, intercurrent ilnness, joint aspiration and blood / fluid infusion.

Management acute gout