Rheumatology Part 1 (Gout)- Paulson (Exam 2)

Question 1

Gout definition?

Answer 1

Recurring attacks of acute arthritis Chronic deforming arthritis

Question 2

Gout epidemiology/RF?

Answer 2

• Men>women
• Pacific islanders
• Alcohol consumption, esp beer
• Red meat, seafood, fructose
• Obesity
• Meds: thiazide & loop diuretics, low dose ASA

Question 3

Gout pathophys:

Answer 3

• Hyperuricemia needed (but doesn’t always mean gout)
• Serum urate levels > 6.8mg/dL
• Monosodium urate (MSU) level has to be high enough for crystals to precipitate (causes inflammation in joints)
• Resolution of acute inflammation is mediated by immune mechanisms (even w/o tx)
• Over time, chronic inflammatory process, leads to tophi (deposits of MSU) formation, erosion of bone, joint injury

Question 4

Gout uric acid balance: Underexcreters v overproducers

Answer 4

Underexcreters (majority):

• Renal insufficiency
• Meds: diuretics (loop/thiazide), ASA, levodopa, ethambutol, pyrazinamide)
• Acidosis (dka, ketogenic diet, lactic acidosis)
• Volume depletion/dehydration
• Lead exposure

Overproducers (minority):

• Inherited defect of metabolism
  
  • Lesch-Nyhan syndrome
  • Kelley-Seegmiller syndrome
• Myeloproliferative and lymphoproliferative disorders, polycythemia, carcinoma
• Chronic hemolytic anemias
• Transient hyperuricemia associated with ATP consumption
  
  • strenuous exercise, status epilepticus, MI, sepsis

Question 5

3 stages of gout?

Answer 5

1. Acute gouty arthritis 2. Intercritical (interval) gout 3. Chronic articular and tophaceous (MSU crystals) gout

Question 6

Acute gouty arthritis sx?

Answer 6

• “My big toe hurts”
• Sudden onset, often at night
• Severly painful and tender, swollen joint, red, warm
• May complain of fever
• Reaches maximal severity in about 12-24hrs
• May have hx of similar attacks prior

Question 7

Seen on acute gouty arthritis exam?

Answer 7

• Swollen, very tender, red, warm overlying skin
• May see desquamation
• May see tophi
• MTP of great toe is classic sign “podagra”
  
  • usually monoarticular and in the lower extremity
  • polyarticular is possible

Question 8

What is tophi?

Answer 8

• Irregular, asymmetric, macroscopic deposits of urate
• Pathognomonic for gout
• Common sites include external ear, hands, olecranon, feet, knee, achilles tendon, forearm
• Usually painless but can become acutely inflamed Usually develop after years
• Maintain state of inflammation
  
  • promote tissue and joint destruction around them

Question 9

Gout renal manifestations?

Answer 9

• Uric acid nephrolithiasis (kidney stones)
• Chronic urate nephropathy
  
  • _​_MSU crystals are deposited in the renal medulla and pyramids
• Uric acid nephropathy
  
  • ARF (acute renal failure) when large amounts of uric acid crystals precipitate in the collecting ducts and ureters
    
    • usually seen as part of tumor lysis syndrome

Question 10

Gout diagnosis?

Answer 10

• Aspirate of synovial fluid showing monosodium urate (MSU) crystals
  
  • “negatively birefringent”, needle-like, when viewed with polarized light microscopy
• US: hyperchoic linear density (double contour sign) over the joint cartilage or deposits that look like tophi
• Radiographs: “rat bite” lesions later in disease process (if next to a tophus=gout)

Question 11

What labs would you order for suspected gout?

Answer 11

• Serum uric acid (can be normal or low, though)
• Peripheral WBC can be high
• ESR/CRP can be elevated

Question 12

How many criteria needed to make clinical dx?

Answer 12

>6 Or MSU crystals in joint fluid or tophus

Question 13

Gout tx?

Answer 13

• If asymptomatic hyperuricemia: don’t treat
• Lifestyle mods:
  
  • lose wt
  • reduce etoh
  • reduce purine-rich food consumption
  • drink lots of water
• Avoid hyperuricemic meds, if possible

Question 14

Tx of acute gout attack?

Answer 14

• Goal is to relieve pt’s pain
• Start tx asap
• Urate-lowering meds (allopurinol) : don’t help in acute attacks so don’t start one

Question 15

Gout tx contraindications for NSAIDs

Answer 15

CKD with CrCl< 60, active ulcer, NSAID allergy, concurrent use of anticoagulant, CV disease (esp uncontrolled CHF or HTN)

Question 16

3 types of Gout meds for acute attack?

Answer 16

NSAIDs 1st choice

• naproxen (Aleve)
• indomethacin
• Discontinue 1-2 days after complete clinical resolution. (Typical course might be 5-7 days)

Colchicine:

• good for pts w/ nsaid intolerance
• commonly causes diarrhea and abd cramping
• possible reversible peripheral neuropathy
• Contraindications: severe hepatic or renal impairment with colchicine use in past 2 wks, concomitant use of a mod-strong inhibitor of P-gp and/or CYP3A4 inhibitor (antifungals, antivirals, some antiarrhythmics)

Corticosteroids:

• good for people who can’t take nsaids or colchicine
  
  • intra-articular injection: triamcinolone
  • oral prednisone
  • IV methylprednisolone
  • IM triamcinolone
• Caution for pts with CHF, glucose intolerance, poor control of HTN

Question 17

How do we prevent gout?

Answer 17

• Adress preventative issues during the intercritical period
• Goal is to achieve a serum urate level <6mg/dL
  
  • Slowly (not > 1-2mg/dL/month)
• use low-dose prophylactic colchicine (or low-dose NSAID) when initiating antihyperuricemic therapy to reduce risk for acute flare

Question 18

Meds for chronic gout?

Answer 18

Xanthine Oxidase Inhibitors (XOI) - reduce production of uric acid

• Allopurinol OR Febuxostat
  
  • Give prophylactic colchicine when initiating

Question 19

Uricosuric meds?

Answer 19

• Block tubular reabsorption of urate and increases the rate that uric acid is renally excreted
  
  • Pt must have nl renal function
• Probenecid
• Do not give to a pt with G6PD (increases risk of hemolysis)

Question 20

Uricase med for gout?

Answer 20

• Enzyme present in other mammals that breaks urate down to allantoin, which is more easily excreted
• For pts who have been refractory to all other therapies
• Pegloticase: given IV q 2 weeks
• Don’t give to people with G6PD

Question 21

Gout prognosis/referral?

Answer 21

• Acute attack will self-resolve even w/o tx
• Over time attacks become more frequent and longer
• W/ urate lowering meds (XO allopurinol or uricase Pegloticase), much less chronic gouty arthritis, tophi, and deformity
• Can refer to rheumatology

Question 22

How is pseudogout different from gout?

Answer 22

• Gout is urate crystal (needle-like) deposition in joints, while pseudogout is calcium pyrophospate dihydrate (CPPD) crystal (rhomboids) deposition, which can mimic gout.
• Gout usually effects the great toe, while CPPD or pseudogout usually effects larger joints such as the knee.

Question 23

What is a sign of CPPD pseudogout seen on plain film radiographs?

Answer 23

Chondrocalcinosis: which look like white deposits in the joint space.

Question 24

What does the typical CPPD pseudogout pt look like?

Answer 24

• Older adults (rare before 55)
• Around 50% of those >85 are affected
• Joint trauma
• Familial chondrocalcinosis
• Hemochromatosis

Question 25

How would you describe an acute CPPD pseudogout attack?

Answer 25

• Self-limited, sudden attack of pain, redness, warmth, disability, and swelling (can be one or several joints)
• Knee is most commonly affected with pseudogout (great toe for gout)
  
  • Others: wrists, shoulders, elbows, ankles Possible chills/fever
• Can be provoked by surgery (parathyroidectomy), trauma, or major illness
• May have associated f/c

Question 26

Chronic CPP crystal inflammatory arthritis is also known as, and can mimic sxs of what autoimmune disease?

Answer 26

• “pseudo RA”
• Similar sx to RA, involving multiple joints in a symmetric pattern (bilat)
  
  • usually affects joints unaffected by OA: MCP, wrists, elbows, glenohumeral joints

Question 27

Pseudogout can also mimic OA, called “pseudo-OA”. Which joint is the most common and what do you see on clinical examination?

Answer 27

• Knee most common for pseudo-OA (also hips, shoulder, spine, etc)
• Clinical exam is like that of OA: tenderness of joints, bony enlargement, crepitus, restriction of motion

Question 28

Pseudo-neuropathic disease is another mimicking diesease of pseudogout. What does it mimic?

Answer 28

• Charcot joint/foot: joint degenerates and collapses from CPP crystal deposition
• Resembles neuropathic arthropathy but w/o neurologic impairment

Question 29

How is a dx of pseudogout vs gout made?

Answer 29

• Pseudogout: “weakly positively birefringent RHOMBOID crystals”
• Gout: “negatively birefringent, needle-like, when viewed with polarized light microscopy”

Question 30

How do you treat an acute pseudogout attack?

Answer 30

• Aspirate the joint then intraarticular glucocorticoid (triamcinolone) injection
• Nsaids: indomethacin, naproxen, salicylates
• Colchicine
• System corticosteroids

Question 31

How do you treat pseudo OA?

Answer 31

Same way as OA Nsaids, steroid injections into joint, joint replacement

Question 32

What prophylactic meds would you give for pseudogout? For pseudo-RA?

Answer 32

Pseudogout:

• Colchicine
• Nsaid

Pseudo-RA:

• nsaids (naproxen, indomethacin)
• Alternative: colchicine, hydroxycholorquine, low-dose glucocorticoids ie: prednisone

Question 33

If the 24 hr urine uric acid test shows <800 mg/d, this means the pt is an undersecreter of uric acid and you should prescribe which class of medication?

Answer 33

Uricosuric agent (Probenecid) or XOI (Allopurinol or Febuxostat)

Question 34

The 24 hr urine uric acid test comes back >800 mg/d, which means your pt is an overproducer of uric acid and you should prescribe which class of medication?

Answer 34

XOI (Allopurinol or Febuxostat)