Crystal arthropathies Flashcards
if you suspect gout, what is the top differential
why
septic arthritis
presents similar but more serious
is gout more common in males or females
males (9:1)
what are the modifiable risk factors of gout (2)
diet - red meat, shellfish, cheese
alcohol
what is the general pathophysiology of gout
increase in urate acid crystals (hyperuricaemia)
aetiology of gout associated with over production of urate crystals (2 + examples)
genetics
high cell turnover - cancer, psoriasis, infection, excessive exercise
which skin condition is associated with gout
psoriasis
bc of high cell turnover
aetiology of gout associated with underexcretion of urate crystals (4)
thiazide diuretics
metabolic issues
renal failure!
starvation
in gout why are the urate crystals deposited in the joints
colder temp than other parts of body
in gout what happens when the crystals are deposited in the joints
inflammation of joint
what type of crystals are associated with gout
urate crystals
triggers for gout flare up (3)
dehydration
trauma
surgery
common locations of gout (3)
1st MTP joint (big toe)!!!!
ankle
knee
how many joints does gout usually involve
name of this
one
monoarthritic
presentation of gout (3)
when (2)
red hot severe pain rapid onset (hours/overnight) lasts <2 weeks
investigations of gout (4)
joint aspiration
inflammatory markers
blood tests
blood cultures
what is the gold standard investigation for gout
joint aspiration
findings of joint aspiration of gout (2)
negative birefringent
needle shaped crystals
why do you need to do a blood test/culture for gout
to rule out septic arthritis
management of gout acute flare up (7)
expose, cool, elevate
antiinflammatory - NSAIDs, colchicine (if NSAID not tolerated), corticosteroids
analgesia
first line prophylaxis of gout flare up (after an acute attack)
allopurinol
lifestyle modification for gout (4)
reduce red meat
reduce shellfish
reduce alcohol
loose weight
what drug would you consider changing if someone was on it and had a gout acute attack
thiazide diuretics
who do you give gout prophylaxis to
> 2 flare ups in 6 months
does gout present on xray
acute attack - no
chronic gout - yes (erosions)
when do you give gout prophylaxis (in relation to the attack)
2-4 weeks after acute attack (when flare up has settled)
what is the mechanism of allopurinol
reduces uric acid production
for gout do you start allopurinol for gout high dose or low dose
why
low dose
lowering uric acid too quickly can cause another acute gout attack
what is an alternative uric acid lowering drug to allopurinol
febuxostat
complications of gout
chronic gout (polyarticular chronic joint inflammation) kidney stones
how can gout result in kidney stones
urate crystals can be deposited in kidney tubules
what is the differential list for someone with monoarthritic joint pain
septic arthritis gout pseudogout enteropathic arthritis (IBD) reactive arthritis
what type of crystals are deposited in pseudogout
calcium pyrophosphate crystals
which group of people are more likely to get pseudogout
elderly
which other MSK condition is pseudogout closely associated with
osteoarthritis
which joints does pseudogout usually affect
knees
wrists
ankles
gold standard investigations for pseudogout
joint aspiration
result of joint aspiration in pseudogout (2)
positive birefringence
rectangular/rhomboid/envelope shaped crystals
whats can differentiate between gout and pseudogout
joint aspiration
is there inflammation in gout
yes
is there inflammation in pseudogout
no
treatment of pseudogout
NSAIDs
colchicine (if NSAIDs not tolerated)
steroids
prophylaxis of pseudogout
none :(
what is hydroxyapatite crystal deposition known as
Milwaukee shoulder
where do hydroxyapatite crystals typically deposit
shoulder
which group of people is Milwaukee shoulder common in
50-60 year old females
investigations for Milwaukee shoulder
alizarin stain (red clumps of calcium) xray of shoulder (crystal deposits)
presentation of Milwaukee shoulder
acute onset should pain
reduced range of movement
renal failure
hot swollen joint
gout - decreased excretion of urate crystals
rare complication of using allopurinol for gout
why
acute gout attack - bc it lowers the serum uric acid
