Crystal Arthropathies

Question 1

what can precipitates gout attacks

Answer 1

acute changes in serum levels of uric acid

Question 2

what causes gout?

Answer 2

overproduction or under-execretion of uric acid causes excessive levels

Question 3

gout patho

Answer 3

overproduction or under excretion of uric acid

urate in serum is supersaturated so It precipitates out into joint to form crystals

MSU crystals trigger inflammatory reaction which is calmed in 1-3 weeks

Question 4

tophus formation is caused by

Answer 4

chronic MSU crystal deposition and gouty attacks

Question 5

solubility of serum uric acid

Answer 5

6.8 mg/dL

Question 6

MC joint in gout

Answer 6

solubility decreases as temp falls so

colder tissue = more risk so more distal joints

Question 7

gouty attacks often follow

Answer 7

local trauma and previous MSU crystal deposits in and around joints

Question 8

MC joint affected ny gout

Answer 8

1st MTP joint –> podagra

Question 9

uric acid metabolism

Answer 9

uric acid is end stage by product of prune metabolism and is normally removed by kidney

90% of pts under excrete uric acid

10% over produce and over eat purine rich food

Question 10

underexcretion causes

Answer 10

chronic kidney dz

drugs

chronic ethanol abuse (beer and hard liquor)

starvation/dehydration

hypothyroid

hyperparathyroidism

Question 11

overproduction of uric acid

Answer 11

high cell tyrnover/lysis

lymphoproliferative dz
psoriasis
cell lysis from chemo

hemolytic anemia

Question 12

excessive uric acid intake

Answer 12

organ meats, anchovies, sardines, sweetbreads

consumption of fructose rich foods and drinks

Question 13

meds that raise uric acid serum levels

Answer 13

(loop or tzd diuretics, low dose aspirin, cyclosporin)

Question 14

meds that decrease uric acid

Answer 14

radio contrast dyes

high dose aspirin

xanthine oxidase inhibitors

uricosurics

Question 15

medical conditions associated with high incidence of gouts

Answer 15

HTN 
DM 
CKD
dyslipidemia/hypertrigleridemia 
obesity
menopause/loss of estrogen

Question 16

uric acid levels and gout

Answer 16

NOT all pts with hyperuricemia develop gout

serum levels of uric acid correlate poorly with risk of developing gout

Question 17

gout clinical presentation

Answer 17

begins abruptly and escalates rapidly, peaking 8-12 hrs

severe pain, swelling and erythema of affected joint and overlying skin

joint is exquisitely tender

MC joints of LE

Question 18

gout should be considered when

Answer 18

pt presents with peripheral monoarticualr arthritis

Question 19

if gout is untreated

Answer 19

more polyarticular and affecting more proximal joints

more frequent and lasts longer but inflammation will be less intense

Question 20

PE of gout

Answer 20

joint will be hot, red, and exquisitely tender with loss of ROM

pt may have systemic signs of inflammation

Question 21

classic location of tophi

Answer 21

helix of the ear

Question 22

ideally gout should be diagnosed if

Answer 22

1. MSU crystals present in joint aspirate

2. infection or other crystals absent from joint aspirate

Question 23

when to get joint aspirate

Answer 23

monoarticular arthritis cases with uncertain H&P

cell count and differential
gram stain and culture
analysis of crystals under microscopy

Question 24

WBC count of crystal arthropathies

Answer 24

elevated due to inflammation

10,000-70,000

Question 25

what type of crystals in gout

Answer 25

MSU crystals

needle shaped intracellular and extracellular crystal

exhibit NEGATiVE BIFRINGENCE