Gout Flashcards
what is gout considered?
a crystal induced arthropathy
what type of crystals cause gout
monosodium urate monohydrate crystals
where can the crystals deposit?
joint, bursae, tendon
are males or females more affected? age?
males
30-60
when tissues become supersaturated, the urate salts precipitate, in the form of needle-like crystals called….
NEGATIVE BIFRINGENT CRYSTALS
what is the role of the WBCs
they attack the negative bifringent crystals and cause an acute attack
uric acid is an end-stage by-product of what?
purine metabolism
how do humans normally remove uric acid
renal metabolism
when might hyperuricemia develop
when the saturation level of uric acid drops below 6.8mg/dL in the urine. then it’’ deposit in the soft tissues
what are the two reasons for accumulation of urate?
over producers (10%) underexcreters (90%)
what are the RFs for over producers
overconsumption of purines (seafood, meat, fructose, soft drinks, wine) OR production of excessive amts of uric acid endogenously ETOH myeloproliferative d/o psoriasis hemolytic anemia cell lysis-chemotherapy excessive exercise
what are the reasons for someone to be an underexcreter?
inability to excrete uric acid in the urine medications kidney dz starvation dehydration chronic ETOH use
what causes an acute flare?
an acute increase or decrease in urate levels that may lead to the production, exposure of shedding of crystals
what can cause changes in levels of urate?
acute alcohol ingestion
acute overindulgence in high purine foods
rapid weight loss
dehydration
can gout be genetic?
yes! 3 genes thought to be involved
what is the MC presentation?
when does it reach max intensity?
when does it improve?
commonly starts as monoarticular
1st MTP - “Podagra”
12-24 hrs
improvement of sx within days to weeks
what might you see on a severe attack (hint: it might look similar to a septic arthritis)
severe pain, redness, warmth, swelling
+/- fever
you may have arthritis at other sites (finger joints, instep, ankle, knee)
what can happen to attacks over time?
they become more severe and polyarticular over time
what if attacks are left untreated?
they become more frequent and abate more slowly with time
what is the stage of gout when they “get out of their attack”
intercritical gout
20 years of untreated urate deposition can lead to
chronic tophaceous gout
what are tophi
urate crystal masses surrounded my inflammatory cells and fibrosis
what are the characteristics of the tophi
firm, movable, yellowish. they ulcerate with chalky material
where are some common places to have tophi
pinna of the ear over involved joints extensor surfaces of the forearm olecranona infrapatellar Achilles tendon
diagnosis of acute attack
arthrocentesis - urate crystals in joint fluid are diagnostic (neg biferengent - bright yellow)
plain radiographs - erosions with overhanging edges
why must you get the sample from the athrocentesis to the lab right away?
over time, the crystals dissolve
what is the WBC count in the synovial fluid?
high!
>15,000 but usually
what is out goal in an acute attack?
relieve pain and inflammation
*note: symptoms do resolve on their own in weeks, but treating with meds improve sx more quickly
1st line
2nd line
3rd line
for acute attacks of gout
NSAIDS (Indomethacin or Naproxen)
Colchicine
Glucocorticoids (oral or intra-articular)
what are the contraindications to NSAID use?
CKD with Cr clearance
when should tx with NSAIDs be stopped?
1-2 days after clinical symptoms resolve
when is Colchicine used and what is its MOA?
for pt with NSAID intolerance or with an absolute indication to NSAID use
Inhibits neutophil chemotaxis and inflammatory mediator release
only used for gout
(still gonna have to give em something for pain)
what are the two options for glucocorticoids?
prednisone (oral), triamcinolone (intraarticular)
should you use the intraarticular triamcinolone if you have more than 1 or 2 joints involved?
no
what helps with gout risk reduction?
weight loss
reduce ETOH intake
stop diuretic
stop ASA
what do diuretics and ASAs do?
increase serum urate levels
when should you start prophylaxis (urate lowering therapy)?
2 weeks after acute flare has resolved
what are the 3 options for intercritical period treatment (prophylaxis)
Probenecid
Allopurinol
Febuxostat (Uloric)
what is the MOA of probenecid and what are the contraindications
promotes renal clearance of uric acid by inhibiting urate anion exchangers in the proximal tubule that mediates urate reabsorption.
CANNOT use in pts with nephrolithiasis or impaired renal function.
mult doses/day
MOA of Allopurinol and Febuxostat (Uloric)
xanthane oxidase inhibitor (xanthane oxidase produces uric acid)
what are the SE’s of Allopurinol
mild rash may disappear if stop then restart
diarrhea and GI distress
can cause hypersensitivity syndrome of eosinophilia, fever, hepatitis, poor renal funx, erythematous desquamative rash.. stop if it develops bc it could lead to SJS, TEN
allopurinol + what antibiotic causes rash in 20%
ampicillin
what is more effective for hyperuricemia than allopurinol but more expensive
Febuxostat (Uloric)
does Uloric have a hypersensitivity reaction like allopurinol?
nope
what is CPPD
calcium pyrophosphate deposition disease
what type of crystals are seen in CPPD
calcium pyrophosphate crystals
what do the calcium crystals in CPPD cause
chondrocalcinosis (deposits on cartilage)
is CPPD mono or poly articular?
can be both
what is the initial location for CPPD
knee
whats the onset of CPPD compared to gout
slower
what does joint fluid show for CPPD
rhomboid crystals
what is the tx for CPPD
joint aspiration and NSAIDS
