25: Crystalline Arthropathies - Craig

Question 1

serum urate

Answer 1

formed in process of purine metabolism/degradation

Question 2

hyperuricemia ***

Answer 2

serum urate values in excess of 6.8 mg/dl

higher levels = more risk

Question 3

gout

Answer 3

inflammatory arthritis developing as a consequence of urate deposition in joint

Question 4

4 stages of gout

Answer 4

asymptomatic hyperuricemia (elevated serum urate with no clinical manifestations)

acute flares (acute inflammationin joint caused by urate crystallization)

intercritical segments (intervals between flares)(progressively shorter)

advanced gout (long-term gouty complications of uncontrolled hyperuricemia)

Question 5

why is incidence of gout rising?

Answer 5

• increased longevity
• increased comorbidity
• low dose ASA
• thiazides
• CSA (cyclosporine)
• fructose
• decreased HRT

Question 6

catalyzes the final conversions to uric acid

Answer 6

xanthine oxidase

purine degradation to uric acid

Question 7

medicines that are risk factors for gout

Answer 7

• diuretics [lead to increased uric acid reabsorption]
• low dose ASA [ over 6% increase in mean serum urate and 23% decrease in uric acid clearance]
• pyrazinamide, ethambutol, niacin [observed at higher incidence]

Question 8

why is transplant pt a risk factor for gout?

Answer 8

• attributed to cyclosporine (azathiprine) use

- see an accelerated clinical course with polyarticular involvement and tophi

Question 9

which foods are related to gout?

Answer 9

• red meat
• seafood
• dairy products are PROTECTIVE
• NOT purine-rich vegetables

Question 10

which alcohol is worst for gout?

Answer 10

beer is worse than liquor or wine

Question 11

what medical comorbidities are assoc with gout

Answer 11

• obesity
• metabolic syndrome
• DM
• heart failure
• hyperlipidemia
• hypertension

Question 12

gold standard gout diagnosis ***

Answer 12

synovial fluid analysis - MSU crystals visible with compensated polarized light

Question 13

ddx gout

Answer 13

• CPPD pseudogout

- septic arthritis

Question 14

chronic gout xray

Answer 14

• overhanging edge **
• erosions demarcated round deficits with sclerotic margins
• very destructive

Question 15

*** goals of gout therapy

Answer 15

1. terminate acute attack**
2. prevent recurrence while lowering serum urate
3. prevent or reverse complications from deposition of monosodium urate or uric acid crystals (kidney disease, joint destruction)
4. address comorbidity
5. DO NO HARM

Question 16

IV colchicine

Answer 16

NO don’t do it

Question 17

acute tx gout

Answer 17

intraarticular corticosteroids

Question 18

goal urate level

Answer 18

less than 6 mg/dL

Question 19

uricosuric agents

Answer 19

probenecid

- pee out the uric acid

Question 20

xanthine oxidase inhibtors

Answer 20

allopurinol and febuxostat (stop uric acid production)

Question 21

advantage/disadvantage uricosurics

Answer 21

+ reverse most common physiological abnormality in gout = underexcretion

• BID to TID dosing
• dependent on renal function
• drug-drug interactions

Question 22

number one side effect allopurinol ***

Answer 22

• precipitation of acute attack [lowering serum urate mobilizes deposited crystals]

Question 23

important drug interactions with allopurinol

Answer 23

• azathioprine
• 6-mercaptopurine
  (require xanthine oxidase for breakdown)

Question 24

how long a protective med and allopurinol?

Answer 24

3-6 mo or longer!
12 mo is good
don’t start or stop allopurinol in the midst of an acute flare- allopurinol is a life-long drug

Question 25

CPPD =

Answer 25

calcium pyrophosphate dihydrate deposition disease

• formation of CPPD crystals in articular hyaline and fibrocartilage
• when these crystals produce inflammatory arthrtisi = pseudogout

Question 26

radiographs CPPD

Answer 26

chondrocalcinosis

Question 27

clinical classifications of pseudogout

Answer 27

A: pseudogout
B: pseudorheumatoid arthritis
C: pseudoOA with acute attacks
D: pseudoOA w/o inflammation
E: asymptomatic/lathaic
F: pseudoneurotrophic

Question 28

when in life is pseudogout more likely?

Answer 28

strong age correlation, especially prevalent in 8th and 9th decades

Question 29

4 Hs associated with pseudogout **

Answer 29

• only HEMOCHROMATOSIS assoc with structural arthropathy
• hypomagnesmia
• hyperparathyroidism
• hypophosphatasia
• hemochromatosis

Question 30

most common cause of acute monoarthritis in eldery

Answer 30

pseudogout