Gout / Pseudogout


  • 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. Joint aspirate WCC can be v high
  • In CUH, send to cytology lab for crystal micropscopy(processed OOH if discussed with consultant cytologist)
  • C & S samples

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.


  • 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 include haemochromatosis, hyperparathyroidism, ↓Mg++, ↓PO4, Wilson’s disease, gout and ochronosis
  • Triggers include trauma, intercurrent illness, joint aspiration and blood / fluid infusion
  • More.....

Management acute gout

  • NSAIDs - Indomethacin or Etoricoxib (Arcoxia) are first line drugs
  • Avoid aspirin as raises uric acid levels!
  • Colchicine is effective but causes diarrhoea/cramps
  • Patient advice sheet

Content by Dr Íomhar O' Sullivan. Last reviewed Dr ÍOS 20/08/23.