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. 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.
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 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