Gout Flashcards
Definition
Inflammatory response to the deposition of monosodium urate crystals in joints
Clinical features
- acute monoarthropathy of distal joint “podagra”
- sudden onset
- Red, hot, swollen, tender joint
- systemic symptoms
- Prodromal symptoms
- very painful, joint inflammation
- affects 1st MTP Bjoint of foot BIG TOE - “podagra”
- can affect any joint
- elderly
Causes
Primary
- hyperuricaemia due to genetic predisposition
Scondary
- PRCV- too much nucelic acid/purine Increase urate
- leukaemia - tbx by chemo
- CKD - cant secrete uric acid
pathogeneiss
excess uric acid (breakdown of purine), leads to deposition of urate in joints and soft tissues (tophi)
- acute gout - precipitation in joints stimulate acute inflamm response
- Chronic gout - tophi formation (subcutaenous nodules)
Diagnosis
- Blood tests
- CRP/ESR
- FBC
- SUA levels
- Joint Aspirate
- Polarised light -needle shaped and negatively birefringent
- Gram stain and culture
- X-rays - only soft tissue swelling in early stages. Later well defined punched out lesions
- Measurement of cardiovascular risk
- Primary versus secondary cause
Management of acute gout
Bed rest and cold packs
Analgesia
- NSAIDs - high dose rapidly reduces pain
- COX-2 Inhibitor
Colchicine
Steroids - intra-articular, oral
Interleukin-1 Antagonist
If reccurent - allopurinol - xanthine oxidase (stops [rpduction of uric acid)
urisocuric agent - increased secrretion of uric acid into urine
Management of chronic gout
Lifestyle modification/avoidance of risk factors
- weight loss
- restrict alcohol
- dietary modification
- avoid certain medications
Uric acid lowering therapy should be initiated in following circumstances:
- recurrent attacks
- tophi
- chronic gouty arthritis
- renal disease
- urate lithiasis
- SUA >0.54
- Diuretic use cannot be avoided
- failure of lifestyle modification to lower SUA
Uric acid lowering therapy
Three methods:
- inhibit produciton (allopurinol or febuxostat)
- increase breakdown (pegloticas)
- increase excretion
Allopurinol
- Xanthine oxidase inhibiter
- check renal function prior to commencing
- usually start at 100mg and titrate up to maximum dose of 900mg daily
- Colchicine or NSAID cover
- check SUA monthly and maintain <0.36 mmol/l
- Side effects - mild rash, hypersensitivity reaction, drug interactions
Febuxostat
- For those unable to tolerate allopurinol
- Non-purine xanthine oxidase inhibitor
- Start at 80mg/day
- Titrate to 120mg/day
- Maintain SUA <0.36 mmol/L
Prevention of attacks
- lose weight
- avoid prolonged fasts, alcohol excess, purine rich meats and low dose aspirin
Prophylaxis
- Start if >1 attack in 12 months, tophi or renal stones
- the aim is to decrease attacks and prevent damage cause by crystal deposition
- Use allopurinol and increase every 2 weeks
- Introduction of allopurinol may trigger an attack so wait until 3 weeks after an acute episode and cover with regular NSAIDs or colchicine
