11: Gout - Bennett

Question 1

define gout

Answer 1

An acute arthritic process, which develops from the accumulation of uric acid

Question 2

initial presentation of gout

Answer 2

Initial presentation is usually a painful attack of monoarticular arthritis

Question 3

who gets gout?

Answer 3

Usually affect men older than 25 and women who are post-menopausal

Various precipitating factors (trauma, alcohol, surgery, diet, and drugs

Question 4

primary vs. secondary gout

Answer 4

Primary Gout: may be inherited as idiopathic or secondary to a defect in purine metabolism leading to an overproduction of uric acid.

Secondary Gout: may be the result of an inherited disorder (Lesch-Nyhan or glycogen storage) or the result of over production due to increase of cellular turnover, or in under secretion.

Question 5

where does gout first occur?

Answer 5

first metatarsalphalangeal joint

Question 6

DDx gout

Answer 6

Crystal arthropathies
Infection (cellulitis or osteomyelitis or septic gout)
Sarcoidosis
Trauma

Question 7

symptoms of gout

Answer 7

Pain of the involved joint
Redness
Swelling
Mild fever and chills

Question 8

four phases of gout

Answer 8

• Asymptomatic Hyperuricemia
• Acute Gouty Arthritis
• Intercritical Gout (still has high uric acid, had one acute gouty attacky, may have another attack)
• Chronic Tophaceous Gout (continuous high uric acid with deposits in joint, soft tissue, not necessarily assoc with pain)

Question 9

criteria for diagnosis for acute gout

Answer 9

A. The presence of characteristic urate crystals in the joint fluid (if a past attack then C1 and C4 also)
B. A tophus proved to contain urate crystals by chemical means or polarized light microscope and C1 and C4
C. Presence of six of the following 12 clinical, laboratory, and radiographic phenomena:

1. Maximum inflammation developed within one day **
2. More than one attack of acute arthritis
3. Presents with monoarticular arthritis
4. Redness is observed over the affected joint(s)
5. First metatarsophalangeal pain or swelling
6. Unilateral first metatarsophalangeal joint attack
7. Unilateral tarsal joint attack
8. Tophus is suspected
9. Hyperuricemia
10. Asymmetric swelling within a joint
11. Subcortical cysts without erosions in radiograph
12. Joint fluid culture negative for organisms

Question 10

gout work up

Answer 10

• Blood work
  (serum uric acid level 3-7mg/dl) often blood normal during the acute attack
• Joint aspiration: *** synovial fluid analysis
  • normal is Thick straw colored fluid, Glucose level (same as blood serum), WBC (should not be present)

Question 11

tophi (gout) under microscope ****

Answer 11

Negatively birefringent crystals seen under a polarized microscope

Question 12

pseudogout under microscope **

Answer 12

Weakly positive birefringent rhomboid crystals under polarized scope

Question 13

RA vs. gout periarticular erosions

Answer 13

gout are bigger (5cm +) than RA erosive changes

Question 14

why attack the 1st MPJ?

Answer 14

An increase in uric acid will decrease the solubility resulting in crystal formation.

• Trauma of walking initiates a low grade inflammation resulting in a lower pH.
• Decrease in temp of toe
• Cooling of the extremities and decrease heart rate while sleep. (acute flare ups often happen at bedtime)

Question 15

tx acute gout

Answer 15

• NSAID’S
• Colchicine (antiinflammatory and breaks down)
• Corticosteroids
• analgesics

Question 16

long term gout management meds

Answer 16

allopurinol: blocks formation of uric acid
50 - 300 mg/day

probenecid: increases excretion of uric acid in urine
250-500 mg/day

Febuxostat/uloric 40-80 mg/day
short and long term

Question 17

drug of choice acute gout attack

Answer 17

Initiate NSAIDs (indomethacan) at maximum dosage until 24 hours after resolution of attack, then taper dosage over 2-3 days

if NSAIDs contra, use colchicine

if NSAIDs and colchicine contra, use coritcosteroids (help inflammation only)

Question 18

prophylaxis of acute attack tx

Answer 18

colchicine - discontinue after 1-3 mo w/o attack

Question 19

tx hyperuricaemia

Answer 19

allopurinol

Uricosuric agents (e.g. probenecid, sulfinpyrazone) may be used as an alternative in patients who
are younger than 60 years
have normal renal function
underexcrete uric acid
(

Question 20

Foods with High and Moderate Purine Content

Answer 20

High* : Bacon, Fish: anchovies, codfish, herring, salmon, sardines, trout, Kidneys, Liver, Shellfish: mussels, scallops, Veal, Venison
Turkey

workout with high muscle break down can also stimulate attack

moderate: Shellfish:  lobster, crabs, shrimp, oysters
Asparagus
Beef			  
Duck		     
Ham			
Kidney beans     
Spinach
legumes

Question 21

acquired causes of sustained hyperuricemia

Answer 21

Alcohol consumption
Exercise
Fructose Consumption
High purine intake
Myeloproliferative disorders
Obesity and hypertriglyceridemia

Question 22

acquired causes of reduced urate excretion

Answer 22

Drugs (diuretics, low-dose salicylate (aspirin) , and cyclosporine)
Intrinsic renal disease
Metabolites (lactate, ketones, angiotensin, and vasopressin)
Renal causes (plasma-volume concentration, hypertension, urine flow 1 mL/min)

genetic –> Reduced clearance or fractional excretion of urate

Question 23

The development of a stone or calculus composed of urate precipitate within the bladder, ureter, or the renal pelvis

Answer 23

Uric acid Lithiasis

When the concentration of uric acid in urine exceeds its solubility at the urine pH, uric acid changes from a compound dissolved in solution to an insoluble precipitate.
Urate stones are formed by 1 of 3 general mechanisms:
overproduction,
increased tubular secretion,
decreased tubular reabsorption.

Question 24

adult v. child uric acid stones on radiograph

Answer 24

Uric acid stones are the most common cause of radiolucent
stones in children

Uric acid stones in adults tend to be non-visible on radiograph

Question 25

diagnosis and tx uric acid stones

Answer 25

Uric acid stones are usually diagnosed by the symptoms of pain and occasionally blood in the urine

Work-up:

• 24 hour urinalysis
• Ct scan
• urine chemistry

Treatment: hydration

Question 26

T1 MRI

bones and fat

Answer 26

white