Lec 6 Crystal Synovitis Flashcards
What crystal found in acute gout?
monosodium urate
What crystal found in pseudogout?
calcium pyrophosphate
Who typically gets gout?
men more than women plus women after menopause
familial association
What is clinical course of gout?
long phase of asymptomatic hyperuricemia with development of acute attacks; intercritical period between attacks
What is chronic tophaceous stage of gout?
pure precipitates of uric acid precipitate in different parts of body –> tophi on external ear, olecranon bursa, achilles tendon, etc
What are some causes of hyperuricemia due to overproduction?
- lesch nyhan syndrome [absent HGPRT]
- excess PRPP synthetase
- tumor lysis syndrome
- von gierke disease [G6P deficiency]
- psoriasis
- ethanol
What are some causes of underexcretion of uric acid?
- low dose aspirin, diuretics
- dehydration
- renal insufficiency
- largely idiopathic
Is most gout due to overproduction or underexcretion?
overproduction 10%
underexcretion 90%
What happens in acute gout arthritis?
- abrupt onset severe joint inflammation; often at night
- subsides in 3-10 days
- first attack usually in MTP joint of big toe = podagra
- may have hyperuricemia
- swollen, red, painful joint
What causes the inflammation in acute gout?
crystals activate neutrophils which then phagocytize them
What are risk factors for gout?
age > 65 genetic alcohol diuretics obesity
What does the synovial fluid of acute gout look like?
inflammatory WBC > 5,000 [up to 100,000] 90% polys normal glucose positive intracellular neg birefringent uric acid crystals
What is treatment of acute gout?
NSAIDS [indomethacin]
glucocorticoids
colchicine
DON’T USE URIC ACID LOWER AGENTS IN ACUTE ATTACK
What is treatment of chronic gout?
- diet/med modification
- colchicine prophylaxis
- xanthine oxidase inhibitors [allopurinol, febuxostat]
What happens to joint space in gout?
joint space preserved
What medication do you give to an under-excretor?
uricosuric agent –> probenecid
What medication do you give to an overproducer?
zanthine oxidase inhibitor –> allopurinol, febuxistat
What do you see in synovaial fluid in pseudogout?
- inflammatory
- WBCs > 5000
- 90% polys
- normal glucose
- positive intracellular positive birefringent Ca pyrophosphate
What do you see on xray in pseudogout?
chondrocalcinosis
What joints affected in pseudogout?
large joints; classically knee > ankle > writs > shoulder
What are 4diseases associated with pseudogout?
- OA
- hyperparathyroidism
- hypoparathyroidsim
- hemochromatosis
What is treatment for pseudogout?
NSAIDs; steroids; colchicine
What should you think if acute pseudogout in young person?
- wilsons or hemochromatosis
What is milwaukee shoulder?
arthritis of Ca hydroxy-apatite deposition = severe refractory synovitis
seen in elderly women; only effects shoulder; usually dominant arm
