Gout

Question 1

Gout is an excessive amounts of

Answer 1

uric acid (end product of purine metabolism)

Question 2

What are the signs of Gout Arthritis?

Answer 2

Recurrent episodes of acute arthritis, large crystalline aggregates called tophi, and chronic joint deformity

Question 3

Gout has precipitation of

Answer 3

Precipitation of monosodium urate crystals

Question 4

Factors that contribute to Gout

Answer 4

Age of the individual and duration of the hyperuricemia: usually after 20to 30 years of hyperuricemia

Genetic predisposition: X-linked abnormalities of HGPRT, primary gout multifactorial inheritance

Heavy alcohol consumption

Obesity

Certain drugs (e.g., thiazides) reduce excretion of urate and predispose to the development of gout

Lead toxicity

Question 5

Primary gout is

Answer 5

Overproduction of uric acid Normal excretion (majority) Increased excretion (minority)

Question 6

Secondary Gout

Answer 6

Increased nucleic acid turnover ( leukemias )

Renal causes (Reduced excretion of uric acid with normal production (80 to 90% cases)

Inborn errors of metabolism (Lesch-Nyhan syndrome: (Overproduction of uric acid, increased urinary excretion - complete HGPRT deficiency

Question 7

What is the morphology of Gout arthritis

Answer 7

Neutrophil infiltrate in synovium/synovial fluid

Needle-shaped monosodium urate crystals in cytoplasm of neutrophils and in synovium

Synovium is edematous and congested

Synovium: forms pannus

Location: articular cartilage of joints and peri-articular ligaments, tendons, soft tissue of ear lobes, nasal cartilages, skin of fingertips

Question 8

What is Tophi?

Answer 8

pathognomonic, urate crystals surrounded by lymphocytes, macrophages, and foreign-body giant cells, attempting to engulf the masses of crystals

Question 9

In Gouty Arthritis, how does the synovial fluid look with special polarization?

Answer 9

Negative birefringence (yellow)

Question 10

Pathogenesis of Gout arthritis

Answer 10

1. Hyperuricemia
2. precipitation of rate crystals in joints
3. activate complement pathway
4. Neutrophil chemotaxis
5. Phagocytosis of crystals by neutrophils
6. lysis of neutrophils and release of lysosomal enzymes

Also

1. phagocytosis of monocytes
2. release iL-1, TNF, IL-6
3. release proteases

Question 11

Clinical features of Gout arthritis

Answer 11

95% cases in men > 30 years of age

Question 12

Acute gouty arthritis

Answer 12

Mostly first attack is mono-articular; 50% in 1st metatarsophalangeal joint (great toe)

Question 13

Four stages of gout

Answer 13

(1) asymptomatic hyperuricemia
(2) acute gouty arthritis
(3) “intercritical” gout
(4) chronic tophaceous gout

Question 14

Asymptomatic hyperuricemia

Answer 14

around puberty in males and after menopause in women

Question 15

Intercritical period:

Answer 15

Untreated acute arthritis may last for hours to weeks, but it gradually resolves and patient becomes asymptomatic

Question 16

Chronic tophaceous gout:

Answer 16

After a decade of recurrent attacks, radiographs show characteristic juxta-articular bone erosion caused by the crystal deposits and loss of the joint space leading to severe crippling disease

Question 17

Treatment of Gouty arthritis

Answer 17

Non-pharmacologic - modify diet to eliminate diets high in purine, moderation in alcohol intake

Pharmacologic Rx
Acute gout: NSAIDs or colchicine (if intolerant then corticosteroids)

Chronic treatment to normalize serum uric acid:
Uricosuric agents for underexcretors (e.g., probenecid)

Allopurinol (xanthine oxidase inhibitor) for overproducers

Question 18

Pseudogout is caused by

Answer 18

Calcium pyrophosphate crystal deposition disease

Question 19

Most common joint involved in Pseudogout is

Answer 19

the knee

Question 20

Pseudogout happens in which population?

Answer 20

elderly population ( 50% of patients who are 85 years old )

Question 21

What is the pathogenesis of Pseudogout?

Answer 21

CPPD disease: ↑ with
Hemochromatosis, hemosiderosis – Iron is presumed to inhibit pyrophosphatase accounting for decreased degradation of pyrophosphate
(2) Primary hyperparathyroidism (HPTH) - Increase in calcium

Chondrocalcinosis: linear deposits of calcium pyrophosphate in articular cartilage

Question 22

Pseudogout is what type of birefringence?

Answer 22

Calcium pyrophosphate: positive birefringence

blue

Question 23

Suppurative Arthritis is caused by?

Answer 23

Haemophilus influenzae in children <2 years
S. aureus in older children and adults

Gonococcus in late adolescence/young adulthood (more in women)

Individuals with sickle cell disease – Salmonella

Septic arthritis/tendinitis due to cat/dog bite - Pasteurella multocida

Question 24

Suppurative Arthritis is characterized by?

Answer 24

Sudden onset of pain, redness, and swelling of the joint with restricted range of motion

Fever, leukocytosis, and elevated ESR (but in gonococcal infections – subacute)

In 90% of nongonococcal suppurative arthritis, single joint - usually the knee, followed by hip, shoulder, elbow, wrist, and sternoclavicular joints

Joint aspiration is typically purulent,allows identification of the causal agent

Deficiency of C6-9 predisposes to disseminated gonococcal infections (septic arthritis involving knee, tenosynovitis and dermatitis of the wrists & ankles)

Staphylococcus aureus - most common non-gonococcal cause, Treatment: Nafcillin + cephalosporin (third generation)

Question 25

Lyme Arthritis is caused by

Answer 25

spirochete Borrelia burgdorferi, transmitted by deer ticks of the Ixodes ricinus complex

Question 26

What are the stages of Lyme Arthritis?

Answer 26

Stage 1 : days, early localized, erythema chronicum migrans

Stage 2 : weeks, early disseminated
Flu like illnes, Cardiac, Neurologic symptoms

Stage 3 : months to years, Late
Lyme arthritis, Encephalopathy/ neuropathy (bilateral Bell’s palsy)

Question 27

Lyme Arthritis biopsy isn’t useful to diagnose, so what should you use?

Answer 27

Catch it in the 1st stage!

Question 28

What is Neuropathic arthropathy (Charcot’s joint)?

Answer 28

Because of Diabetes Mellitus, they lose sensation in the feet, they keep falling over or tripping, damaging the joint.

Question 29

Is Charcot’s joint inflammatory?

Answer 29

no