Gout

Question 1

Discuss the classification of gout.

Answer 1

Primary gout:

a. 95% of cases
b. genetic disorder characterised by uric acid.
c. Overproduction
d. under-secretion
e. occurs in elderly males and has a strong familial tendency

Secondary gout:

a. 5% of case
b. is due to acquired condition which cause uric acid
c. overproduction
d. under-secretion

Question 2

Can pharmaceuticals cause gout? Discuss briefly.

Answer 2

Many drugs may induce acute gout by their effect on uric acid levels eg some diuretics and salicylates cause increased tubular reabsorption of uric acid.

Question 3

Briefly discuss the pathology of acute gouty arthritis.

Answer 3

1. Urate crystals are deposited in minute clumps in connective tissues (including articular cartilage).
2. These crystals remain within the connective tissue sites for a period of time.
3. Local trauma causes dispersion of crystals into the joint/surrounding tissues.
4. The crystals evoke an acute inflammatory response by:
   • stimulating increased synthesis of inflammatory mediators
   • phagocytosis of crystals by neutrophils results in release of lysosomal products which results in the attraction of further WBC’s etc
   • phagocytosis of crystals by macrophages results in secretion of IL-1(a potent inflammatory mediator)
5. The urate crystals that evoke the acute attack of gouty arthritis are:
   • microcrystals
   • birefringent (under polarised light)
   • needle shaped

Question 4

Briefly discuss the pathology of chronic tophaceous gout.

Answer 4

1. With time recurrent attacks of acute arthritis occur.

2. A gradual build up of urate deposits occurs in:
•	joints   
•	tendons   
•	non articular tissues
•	periarticular tissues   
•	bursae

3. The build up of urate deposits in the joints results in:
   • synovial proliferation
   • pannus formation
4. Pannus formation results in:
   • destruction of underlying articular cartilage
   • eventual destruction of subchondral bone
   • proliferation of marginal bone

Question 5

Write brief notes on tophi. What is their significance?

Answer 5

• Tophi result from chronic urate deposition in various tissues and the ensuing chronic inflammatory response
• Tophi are pathognomonic for gout.
• Common sites of occurrence:
o around the metatarsophalangeal joints of big toes
o Achilles tendons
o olecranon bursae
o pinnae of ears (ie in cartilage)
• Tophi vary in size from 1 mm to several cm in diameter.

Question 6

Describe the typical (stereotypical) gout patient.

Answer 6

• males
• family history of gout
• red faced shitfaced
• > 30 years
• obese
• hypertensive

Question 7

Discuss the clinical manifestations of acute gout.

Answer 7

a. sudden onset of severe joint pain (often nocturnal)
b. joint pain lasts a few days.

Attacks are typically limited to a single joint, however more than one site may be affected.

The skin over the affected part is:
•	tense   
•	red or purplish   
•	shiny   
•	warm   
•	very swollen 

The joint:
• feels hot
• is extremely tender
• is limitation in motion

→ atypical presentations eg: acute pain tenderness ( in heel or sole)

Question 8

Discuss the clinical course of acute gout.

Answer 8

• condition progresses:
o acute attacks last longer ie pain may last weeks
o asymptomatic intervals begin to become shorter eg typically have several attacks/year
o gradually merges into chronic gouty arthritis

Question 9

Discuss the clinical manifestations of chronic gout.

Answer 9

• Recurrent acute attacks may eventually merge into polyarticular gout.

• Joint erosion results in:
o chronic pain
o stiffness
o deformity

• Tophi may be discovered; large tophi may ulcerate through the skin and discharge chalky material.

• In chronic gout we may observe the following renal manifestations:
o calculi: occur in 10-20% of cases
o parenchymal disease (due to deposition of MSU from blood) may result in renal failure
o renal tophi

Question 10

How is gout diagnosed?

Answer 10

• usually based on the clinical picture and physical examination.
• Presence of negatively birefringent urate crystals in the synovial fluid or in phagocytes → DIAGNOSTIC of gout.

Question 11

List the radiological features of chronic gout.

Answer 11

Acute attack: soft tissue swelling.

Chronic gout, may observe:
• joint space narrowing
• secondary OA
• tophi
• characteristic punched out cysts/deep erosions in the para-articular bone ends
• in severe cases bone erosion is marked and resembles neoplasia

Question 12

Briefly discuss the prognosis of gout.

Answer 12

• most patients to live a normal life when the diagnosis is made early and treatment instituted quickly.
• more severe in patients whose initial symptoms and signs appear before 30 years of age.

Question 13

List the complications of gout.

Answer 13

• urolithiasis
• urinary tract infection
• urinary tract obstruction
• renal tubulointerstitial disease