Related Subjects:
|Rheumatoid arthritis
|Systemic Sclerosis (Scleroderma)
|RA vs OA
|Acute and Chronic Gout
|Calcium Pyrophosphate Deposition (Pseudogout)
|Hyperuricaemia
|Allopurinol
|Rasburicase
|Lesch-Nyhan syndrome
โ ๏ธ It is very rare for acute gout to occur in a rheumatoid joint.
๐ Continue treatment until 1โ2 days after the attack has resolved and ensure follow-up.
๐ Admit if septic arthritis is suspected (always exclude this).
๐ Remember: serum urate may be normal during an acute attack, so repeat later.
๐ About
- ๐ Gout is due to deposition of monosodium urate monohydrate crystals in joints and tissues.
- โณ Chronic hyperuricaemia may cause renal failure, nephrolithiasis, and tophi.
- ๐ Drugs in the elderly (thiazides, low-dose aspirin, ciclosporin) are common contributors.
๐งฌ Aetiology
- โฌ๏ธ Overproduction of uric acid (purine metabolism disorders, haematological malignancy).
- โฌ๏ธ Impaired excretion of urate (genetic predisposition in >90%).
- ๐ก Crystals are needle-shaped, negatively birefringent under polarised light.
- ๐ฃ Classically affects 1st MTP joint โ Podagra.
- ๐ Precipitating drugs: thiazides, ciclosporin, aspirin.
โก Effects of Hyperuricaemia
- Often asymptomatic
- Acute gouty arthritis
- Chronic interval gout โ repeated flares on background inflammation
- Polyarticular tophaceous gout โ pain, deformity, joint damage
- Renal urate stone formation and chronic kidney disease
๐ Epidemiology
- Male predominance (M:F โ 10:1)
- Prevalence: ~1โ2% of UK population, especially older men & postmenopausal women
- Attacks often linked to lifestyle factors (alcohol, obesity, diet rich in purines)
๐ฆถ Podagra โ 1st MTP joint (classic site)
๐๏ธ Chronic Tophaceous Gout
๐ฌ Urate Crystals
โ ๏ธ Risk Factors
- ๐จ Male sex (risk ร5โ10 compared to women)
- Age <30 โ suspect enzyme defects or renal disease
- Obesity, alcohol, hypertension, hyperparathyroidism
- ๐ Post-chemotherapy tumour lysis & tissue breakdown
- Pb poisoning (saturnine gout)
- Haematological malignancy, haemolysis, extreme exercise
- LeschโNyhan syndrome (HGPRT deficiency)
๐บ Causes of Excess Urate
- Reduced excretion: CKD, thiazides, aspirin, hypertension, lactic acidosis (alcohol, starvation), glycogen storage disease, lead toxicity, hypothyroidism
- Overproduction: HGPRT deficiency, PRPP overactivity, myeloproliferative or lymphoproliferative disorders, psoriasis
๐ฉบ Clinical Presentation
- Sudden onset (often nocturnal/early morning)
- Severe localised pain, swelling, erythema โ maximal in 6โ12 hours
- Extreme tenderness, sometimes mimicking cellulitis
- Attack lasts 5โ14 days if untreated
- Systemic features: fever, malaise, raised CRP
๐จ Complications
- Chronic tophi โ visible lumps, joint deformity, disability
- Renal stones in ~20% of patients
- Chronic urate nephropathy โ CKD
๐งช Investigations
- Bloods: FBC, U&E, CRP, ESR (raised in acute flares)
- Serum urate: may be normal during flare; repeat later
- Joint aspiration: strongly negative birefringent, needle-shaped crystals
- Radiology: punched-out erosions, soft tissue tophi, osteoporosis
๐ Management
- Acute Attack:
- Rest, elevate, ice, avoid trauma
- Exclude septic arthritis (may need aspiration)
- NSAIDs (e.g. indomethacin, diclofenac) + PPI if tolerated
- Colchicine (1mg stat, then 0.5mg BD/TDS) โ caution diarrhoea
- Oral steroids (prednisolone 10โ15mg for 5โ7 days) if NSAIDs/colchicine unsuitable
- โ ๏ธ Do not stop allopurinol/febuxostat during an acute attack
- Prevention:
- Lifestyle: weight loss, reduced alcohol, avoid dehydration
- Stop thiazides/aspirin if possible
- Urate-lowering therapy if recurrent attacks, tophi, renal impairment, or nephrolithiasis
- Drugs:
- Allopurinol (start 50โ100mg, titrate to 300mg+; dose adjust in CKD)
- Febuxostat (80โ120mg OD if allopurinol fails/intolerant)
- Pegloticase (IV uricase) for severe refractory gout
- Cover initiation with colchicine or NSAID for 3โ6 months (prevents flares)
๐ References