Crystal arthropathy Flashcards
What is gout?
where high blood uric acid levels cause urate crystals to be deposited in the joint causing it to become inflamed
How does gout present?
excruciating, acute, hot, swollen and painful joint (similar to septic arthritis!)
What is the name given to subcutaneous uric acid deposits?
gouty tophi
Name 3 sites where gouty tophi are commonly found in gout:
1) hands
2) elbows
3) ears
Give 8 risk factors for gout:
1) male
2) alcohol consumption
3) family history
4) CVD
5) high purine diet (meat and seafood)
6) kidney disease
7) obesity
8) diuretics
What three joints are most commonly affected by gout?
1) the base of the big toe (metatarsophalangeal joint)
2) the base of the thumb
3) wrist
How is gout diagnosed?
diagnosed?
clinically, supported by a raised serum urate level on blood test
What joint aspiration finding would be in line with gout?
monosodium urate crystals
Describe the composition, shape and properties of gout crystals: (3)
1) monosodium urate crystals
2) needle shaped
3) negatively birefringent of polarised light
Give 4 x-ray findings associated with gout:
1) maintained joint space
2) lytic lesions in the bone
3) punched out erosions
4) sclerotic boarders with overhanging edges on erosions
What is the first line drug for gout in acute episodes?
NSAIDs e.g. naproxen
What drug is prescribed alongside long term NSAIDs?
PPI (for gastroprotection)
What is the second line drug for gout pain relief in acute episodes?
colchicine
What is the third line drug for gout pain relief in acute episodes?
oral steroids (e.g. prednisolone)
What drug class is given for gout prophylaxis?
xanthine oxidase inhibitors
Give two examples of xanthine oxidase inhibitors:
1) allopurinol
2) febuxotsat
When is gout prophylaxis started?
after the first acute attack of gout
What is pseudogout?
a crystal arthropathy caused by calcium pyrophosphate crystals collecting in the joints causing inflammation
True or false: pseudogout typically presents less severely than gout
True
Name 4 joints commonly affected by pseudogout:
1) knee
2) hip
3) shoulders
4) wrist
How does pseudogout present? (2)
1) can be asymptomatic - an incidental X-ray finding
2) acute, stiff, hot, swollen joint
What crystal is found in pseudogout joint aspiration?
calcium phosphate crystals
What shape are calcium phosphate crystals?
rhomboid-shaped
Describe the birefringent properties of calcium phosphate crystals:
positively birefringent of polarised light
Give 5 X-ray findings associated with pseudogout:
1) chondrocalcinosis
2) loss of joint space
3) osteophytes
4) subarticular sclerosis
5) subchondral cysts
Give 4 symptomatic relief treatments of pseudogout:
1) NSAIDs (naproxen) prescribed with a PPI for gastroprotection
2) colchicine
3) intra-articular steroid injections
4) oral steroids
