gout

Close association with cardiovascular risk factors
Etiology Monosodium urate crystals forming in and around joints.
Hyperuricaemia (CKD), drugs (Loop diuretics, thiazides, pyrazinamide), starvation, cytotoxics (Tumour lysis syndrome)
Epidemiology M>F
Clinical presentation Site: 1st metacarpal, base of thumb, ebow; pseudogout: wrist
Pain++, redness, warmth - max intensity within 24h
Previous self-limiting episodes supports diagnosis
Tophi - extensor joint surfaces
Pathogenesis
Diagnostic investigations XR: periarticular erosions
Joint aspirate: negatively birefringent needle-shaped crystals
Management Acute mx: NSAIDs, colchicine PO, f/u after 4-6/52
Colchicine s/e: diarrhoea (dose-dpdt)
• Continue ULT if already established; continue diuretics in HF
• Stage 5 CKD ⇒ steroids instead of NSAIDs

Start urate-lowering therapy after acute attack resolves.
- Allopurinol (xanthine oxidase inhibitor) or febuxostat (needs LFT monitoring)- usually lifelong. (s/e: rash, fever, ↓ WCC)
- Co-prescribe with colchicine prophylaxis
- Review CVS risk factors, lose weight. Monitoring: serum uric acid

pseudogout = calcium pyrophosphate deposition

  • same sites
  • joint aspiration: positively birefringent rhomboid-shaped crystals
  • can still use colchicine/NSAIDs