gout Flashcards
(26 cards)
Gout
form of microcrystal synovitis caused by deposition of monosodium urate monohydrate in the synovium
caused by chronic hyperuricaemia (uric acid >0.45)
if untreated, repeated episodes can caue more chronic joint problems
drug causes of gout
diuretics - thiazides, furosemide
ciclosporin
alcohol
cytotoxic agents
pyrazinamide
low-dose aspirin
gout presentation + commonly affected joints
acute episodes, sx free inbetween
- pain
- swelling
- erythema
joints -
- ankle
- wrist
- knee
gout investigations +
what uric acid level would support a diagnosis?
measure uric acid levels
- >=360 supports diagnosis
- <360 - but sx, repeat 2wks after flare has settled
synovial fluid analysis
xray
what would synovial fluid analysis show in gout
need shaped negatively birefringent monosodium urate crystals under polarised light
radiological features of gout
- joint effusion
- well defined punched out erosions with sclerotic margins in a juxta-articular distribution
- overhanging edges
- eccentric erosions
- soft tissue tophi
NO perarticular osteopenia -> in contrast to RA
which joint does the 1st presentation of gout typically occur
1st metatarsophalangeal (MTP) joint
(base of big toe)
acute management of gout
NSAIDs or colchine = 1st line
- NSAIDs - give PPI, max dose til 2 days after sx have stopped
- colchine - caution in renal disease, slower onset of action
oral steroid (prednis) may be considered if other 2 contraindicated
if patient already taking allopurinol –> it should be continued
main side effect of colchicine
diarrhoea
indications for urate-lowering therapy
(allopurinol)
to all patients after their 1st attack of gout
especially if -
- >=2 attacks in 12months
- tophi
- renal disease
- uric acid renal stones
- as prophylaxis if on cytotoxics or diuretics
first line urate lowering therapy
allopurinol
- wait until inflam has settled, start when patient not in pain
aiming for serum uric acid <360
colchicine or NSAIDs may be used as cover when starting, this may be continued for 6 months
second line urate lowering therapy
fexobuxostat –> only if allopurinol not tolertaed or ineffective
drug used for rapid control of hyperuricaemia
pegloticase
only if persistent + severe sx
lifestyle modifications for gout
reduce alcohol + avoid during attacks
lose weight if obese
avoid foods high in purines - liver, kidneys, seafood, oily fish + yeast products
increase vit C intake -> decreases serum uric acid levels
hypertension management in patients with gout
losartan -> has specific uricosuric action
precipitating drugs should be stopped in attacks e.g. thiazides
gout predisposing factors
decreased excretion of uric acid
- drugs, diuretics
- chronic kidney disease
- lead toxicity
increased production of uric acid
- myeloproliferative/lymphoproliferative disorder
- cytotoxic drugs
- severe psoriasis
hereditary condition that can predispose to gout
Lesch-Nyhan syndrome
- x-linked recessive - only in boys
features = gout, renal failure, neuro deficits, learning difficulties, self mutilation
conditions assoc with hyperuricaemia
hyperlipidaemia + hypertension
pseudogout
microcrystal synovitis caused by deposition of calcium pyrophosphate dihydrate crystals in the synovium
(pseudogout = acute calcium pyrophosphate crystal deposition disease)
pseudogout age range affected
old
younger patients (<60yrs) usually have an underlying risk factor
risk factors for pseudogout
haemochromatosis
hyperparathyroidism
low magnesium, low phosphate
acromegaly
wilsons disease
commonest joints affected in pseudogout
knee, wrist + shoulders
what would a joint aspiration in pseudogout show
weakly-positively birefringent rhomboid shaped crystals
management of pseudogout
aspirate joint fluid to exclude septic arthritis
NSAIDS or
intraarticular, intramuscular or oral steroids
