gout and pseudogout Flashcards
what is gout ?
clinical syndrome caused by inflammatory response to monosodium urate monohydrate crystals which develops secondary to hyperurecemia
when is it rare to see gout ?
in premenopausal women and in children
what is the level where we can say a patient is hyperuremic ?
> 6 mg/dl or >360umol
what is uric acid a metabolite of ?
purine -> hypoxanthine -> xanthine -> uric acid
what are the classification of hyperuricemia ?
underexcretion
overproduction
what are the causes of underexcretion ?
chronic renal failure
drugs ( CAN’T LEAP)
cyclosporin, alcohol, nicotinic acid, thiazides, lasix ethambutol, aspirin, pyrazinamide
idiopathic or genetic
what are the causes of overproduction ?
polycythemia leukemia chronic hemolytic anemia psoriasis cytotoxic drugs used in malignancy ( tumor lysis syndrome)
what are the 3 stages of presentation of gout ?
acute attack
intercritical period
arthropathy / nephropathy
what is the presentation of acute gout ?
affecting the base of the big toe
usually monoarticular
rapid onset with swelling pain and erythema
may have normal urate levels during the attack
fever
raised WCC ESR
where are the non articular depositions in acute gout ?
olecranon bursa and achilles tendon
achilles tendon
what drug should be avoided in an acute attack of gout ?
allopurinol, prolongs attack
what is the presentation of chronic gout ?
main presentation includes the presence of tophi
tophaceous gout
where can we find tophi ?
helix of the ear fingers eyelids olecranon bursa achilles tendon
how do urate crystals appear under polarized light microscopy ?
needle shaped crystals that appear bright yellow (strongly bifrengent)
what are the radiological findings in acute on chronic gout ?
punched out well defined lesion
subarticular cysts
joint space narrowing
what are the radiological findings inn acute gout ?
soft tissue swelling around the first MTP
what is important about the introduction or withdrawal of hypouricemic drugs during attack ?
the introduction or withdrawal of these drugs cannot be done without the use of colchine/NSAIDs as urate levels may change during the attack
how to treat an acute attack ?
cold pack, rest
anti-inflammatory
colchine
short course of oral steroids
what is the main side effect of colchine ?
GIT intolerance - diarrhea
what are the indications of giving hypouricemic drugs ?
tophaceous gout radiographic erosions uric acid nephrolithiasis urate nephropathy recurrent attacks of gout ( 2 attacks a year)
asymptomatic hyperuricemia do we give hypouricemic drugs ?
nope , but modify the risk factors
what are the xanthine oxidase inhibitor drugs ?
allopurinol works for overproduction and underproduction
febuxostat
what kind of clearance does allopurinol have ?
renal clearance
what kind of clearance does febuxostat have ?
hepatic clearance
which drug could be used if the patient has renal impairment ?
febuxostat because it has hepatic clearance
what are the novel therapies available ?
uricosuric drugs
recombinant uricase
Urat-1 inhibitor
IL-1 trap
when can we use uricosuric drugs ?
patients with proper renal funnction
what is the risk of using uricosuric drugs ?
renal calculi
what do recombinant uricase drugs help inn n?
debulking tophi
what is the disadvantage of using recombinant uricase ?
formation of neutralizing antibodies
what other anti inflammatory drug can we use during an attack of gout ?
IL-1 trap
which drug causes a drug-drug interaction with colchicine ?
clarithromycin or azithromycin
what antibiotic can be suitable to avoid drug-drug interaction with colchicine if the patient is allergic to penicillin?
erythromycin due to risk of rhabdomyolysis
what other calcium deposition disease can present with pseudo gout or pseudo arthiritis ?
calcium pyrophosphate dihydrate crystal deposition , which is more common in females
where are the sites of deposition of CPD crytals ?
pubic symphysis knee wrist shoulders intervertebral space
what do the crystals under light microscopy look like in pseudogout ?
clump of pyrophosphate crystals (rhomboid-shaped) in blood stained synovial fluid ( weakly bifringed)
what are the radiological findings in pseudogout ?
calcified hyaline cartilage and fibrocartilage with linear and spotty appearance
well preserved joint space
what are the main precipitants of gout ?
acute illness
trauma
surgery
alcohol
starvation
drugs
