crystal arthropathies Flashcards
what is the overall cause of gout
hyperuricaemia
what are the two causes of hyperuricaemia
increased production of uric acid
reduced excretion of uric acid
give examples of conditions which would cause increased production uric acid
idiopathic HGPRT deficiency increased cell turnover (psoriasis, cancer after chemo) alcohol high dietary intake of purine
in which products is purine found
red meat
seafood
beer
what condition involves a HGRPT deficiency
Lysch Nyhan syndrome
give examples of conditions which would cause reduced excretion of uric acid
CKD
volume depletion e.g. HF
hypothyroidism
drug side effect e.g. thiazide diuretic
what counts as a reduced excretion of uric acid
> 0.42 mmol/L
how is uric acid produced
end product of purine synthesis
what are the purine bases
adenine
guanine
describe the symptoms of acute gout
monoarthropathic
abrupt onset, usually overnight
may have normal uric acid levels during this attack
what is the treatment of acute gout
NSAIDs
colchicine
steroids (oral or IM)
describe the symptoms of chronic gout
chronic joint inflammation
tophi is present
high serum uric acid
may get acute attacks
what is the prophylaxis for gout, when should it be started
2-4 weeks after an acute attack
allopurinol + steroid
febuxostat
NSAIDs
when should life-long prophylaxis be given
> 1 attack per year
renal failure is present
on a diuretic that can’t be stopped e.g. Hf
if undergoing chemo
what are the clinical findings of gout
precipitation of crystal in joints or soft tissues (tophi)
secondary degenerative changes in the joint
renal disease
what are the pathological findings of gout
joint fluid will have needle shaped crystals under cross-polarised light
amorphous eosinophilic debris and inflammation with giant cells
what investigations are done for gout, what would you expect to find
raised inflammatory markers
raised serum uric acid
polarising microscopy of synovial fluid = needle-shaped negatively birefringent crystals
x-rays
what is pseudo-gout also known as
chondrocalcinosis
CPPD
what is the cause of pseudo-gout
calcium pyrophosphate = acute attacks
calcium hydroxylappatite Crystal deposits
what conditions may lead to pseudo-gout
idiopathic hypercalcaemia haemachromatosis ochronsis hypohyroidism
where is hydroxyapatite found, what is it’s role
normal component of bone and teeth, supplies them with their rigidity
what does groups of hydroxyapatite cause
release of collagenases, serine proteinases and IL-1
what are the symptoms of pseudo-gout
asymptomatic
acute or chronic joint pain
milwaukee shoulder
acute and rapid deterioration
what investigations are done for pseudo-gout, what would you expect to find
microscopy = rhomoid shaped crystal, thicker and bigger than needle-shaped rate crystals
x-rays - dense deposits can be seen
what is the treatment of pseudo-gout
NSAIDs colchicine steroids rehydration intra-articular steroid injection physio partial or total arthroplasty
what is the Buzzword for pseudo-gout
milwaukee shoulder
