Discuss the classification of gout.
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
Can pharmaceuticals cause gout? Discuss briefly.
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.
Briefly discuss the pathology of acute gouty arthritis.
- Urate crystals are deposited in minute clumps in connective tissues (including articular cartilage).
- These crystals remain within the connective tissue sites for a period of time.
- Local trauma causes dispersion of crystals into the joint/surrounding tissues.
- 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) - The urate crystals that evoke the acute attack of gouty arthritis are:
• microcrystals
• birefringent (under polarised light)
• needle shaped
Briefly discuss the pathology of chronic tophaceous gout.
- 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
- The build up of urate deposits in the joints results in:
• synovial proliferation
• pannus formation - Pannus formation results in:
• destruction of underlying articular cartilage
• eventual destruction of subchondral bone
• proliferation of marginal bone
Write brief notes on tophi. What is their significance?
• 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.
Describe the typical (stereotypical) gout patient.
- males
- family history of gout
- red faced shitfaced
- > 30 years
- obese
- hypertensive
Discuss the clinical manifestations of acute gout.
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)
Discuss the clinical course of acute gout.
• 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
Discuss the clinical manifestations of chronic gout.
• 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
How is gout diagnosed?
- 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.
List the radiological features of chronic gout.
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
Briefly discuss the prognosis of gout.
- 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.
List the complications of gout.
- urolithiasis
- urinary tract infection
- urinary tract obstruction
- renal tubulointerstitial disease
