Gout Flashcards
What is Gout?
Crystal arthropathy associated with chronically high blood uric acid levels
What are the common joints affected by gout?
- MTPJ of big toe (most common)
- gout crystals heavy > drag down by gravity
- Ankle
- Foot
- Small joints of hand
- wrist
- elbow
- knee
What is Gouty tophi?
- subcutaneous deposits of uric acid
Where does gouty tophi typically affect?
- hands
- elbows ears
What are the differentials for gout?
- Septic arthritis - exclude this
- reactive arthritis
- haemarthrosis
- calcium pyrophosphate deposition (CPPD)
- palindromic RA
What are the causes of gout?
- Underexcretion of uric acid by kidney
- idiopathic
- renal failure
- thiazide, aspirin
- Over production of purines
- high purine diet (shellfish, meat, anchovies)
- Genetic predisposition
- Chemo/radiotherapy
- Lesch Nyhan Syndrome
- Phosphoribosyl Pyrophosphate Synthase Excess
- Von Gierke Disease
What are the RF for Gout?
- Male
- Obesity
- High purine diet (e.g. meat and seafood)
- DM
- Alcohol
- Diuretics
- Existing cardiovascular or kidney disease
- Family history
What is the Px of Gout?
- Plasma saturated with urate acid
- urate acid react c sodium > form monosodium urate crystals
- urate crystals deposit in soft tissues and joints
- tissue damage > gout attack triggered
- influx of neutrophils into joints
- joint swelling > cleared spotaeneously in 10 days
- persistent gout attacks > chronic gout
- permanent deposition of urate cyrstals around joint
What disease are associated c gout?
- CVS diseases
- HTN
- DM
- CRF
How would you Ix for gout?
- Serum urate: high
- can be normal in chronic haemolytic anaemia
- Fluid aspiration
- Joint xray
What are the features of fluid aspiration of gout?
- Needle shaped crystals
- Negative birefringent of polarised light
- Monosodium urate crystals
What are the xray features of gout?
- soft tissue swelling (early stage)
- Lytic lesions in the bone
- Punched out erosions
- Erosions can have sclerotic borders with overhanging edges
How would you Mx gout during acute flare?
- NSAID or Colchicine - first line
- PPI for gastro protection
- Steroids (15mg Pred/day) - if NSAID or Colchicine contraindicated
- for renal impaired
- Ice packs
What are the prophylaxis management of gout?
- Allopurionol
- dec uric acid levels
- febuxostat - if allopurinol contraindicated
- Lifestyle changes
- reduce alcohol intake and avoid during an acute attack
- lose weight if obese
- avoid food high in purines
What is MOA of allopurinol? When can you not initiate Allopurinol?
- xanthine oxidase inhibitor
- before acute attack settles. only when allopurinol started then it can be continued during an acute attack
What drug class is Colchicine?
and what is the MOA?
- anti-gout agents
- tubulin disruption > down regulation of inflammatory patyhway
What are the differentials for gout?
- Septic arthritis
- Olecranon bursitis
- Milwaukee shoulder
- Chondrocalcinosis
- Pseudogout
- Arthritis
- Haemochromatosis
How do you tell the difference between gout and pseudogout on xray?
- Chondrocalcinosis
What is pseudogout?
- microcrystal synovitis caused by the deposition of calcium pyrophosphate dihydrate crystals in the synovium
What are the RF of pseudogout?
- Increasing age
- If pseudogout develop younger (<60)
- haemochromatosis
- hyperparathyroidism
- low magnesium, low phosphate
- acromegaly, Wilson’s disease
What are the features of pseudogout?
- knee, wrist and shoulders most commonly affected
- joint aspiration: weakly-positively birefringent rhomboid-shaped crystals
- x-ray: chondrocalcinosis
- in the knee this can be seen as linear calcifications of the meniscus and articular cartilage
How would you Mx pseudogout?
- aspiration of joint fluid, to exclude septic arthritis
- NSAIDs or intra-articular, intra-muscular or oral steroids as for gout
