Gout Flashcards
Gout is characterized by ____ deposition throughout the body
uric acid crystalline
(sodium monourate crystals)
Uric acid is a normal byproduct of ____
purine metabolism
What population is primarily affected by gout?
older (40-50s) men (9:1)
(males naturally produce more uric acid than females)
What is elevated in the blood to predispose someone to gout?
uric acid
What are the potential causes of gout?
- idiopathic impairment of renal uric acid excretion (85%)
- genetic problem w/ purine metabolism
- alcoholism (beer & red wine)
- diabetes (long-term, poorly controlled) damages renal function
- stress-induced (?)
Why do beer and red wine predispose someone to gout?
- high in purines
- may lead to renal disease
Describe the pathogenesis of gout prior to diagnosis
- overproduction of purine metabolic byproducts (uric acid)
- inability to dispose of/break down metabolic byproducts
- asymptomatic = hyperuricemia (uric acid crystals are not irritating)
- eventually symptomatic = gout Dx
Most cases of gout are (primary/secondary)
secondary
What is primary gout?
due to metabolic overproduction of uric acid
What is secondary gout?
due to presence of underlying pathology
What underlying pathologies can lead to gout?
- Renal disease
- Multiple myeloma (Bence Jones proteins)
- Alcoholism (red wine & beer)
- Diabetes
Describe the pathogenesis of gout that prompts a diagnosis.
- Urate (sodium monourate) crystals precipitate into periarticular soft tissues
- Urate crystals phagocytized by PMNs + macrophages, inducing intense inflammatory reaction
- Takes average 7yrs to see radiographic findings
Describe the pathogenesis of chronic gout.
- lysosomal & other enzymes released lead to jt. destruction
- if untreated, generally resolved in ~1wk
- can recur months to years later
What is often the initial joint affected by gout?
big toe
Gout in the big toe is called ____
Podagra
What is the initial clinical manifestation of gout?
- acute arthritic pain begins at night, builds rapidly over 24hrs
- begins as 1 big, red, swollen joint (cardinal signs)
- avoids wearing shoes/socks
- lasts 1-2 weeks
- remission of varying lengths
- hyperuricemia
What would be on your differential diagnosis list for a patient with 1 big, red, swollen joint within a day?
- septic arthritis
- gout
- cellulitis
- osteomyelitis
How would you differentiate Gout from Septic arthritis?
- labs
- joint aspiration (pus vs clear w/ crystals)
What locations are commonly affected by gout?
- big toe
- instep
- heel
- ankle
- knee
- wrist
(peripheral jts.; NOT in the spine) - can also affect bursa, tendon sheathes (soft tissues)
What are the late stage findings of chronic gout?
- Tophi
- renal impairment
The chalky crystalline deposits that accumulate in soft tissues over 10-20 years in gout is called ____
Tophi (tophus = sing.)
What clinical manifestation is pathognomonic for gout?
Tophi
What are the 4 stages of gout?
- asymptomatic hyperuricemia
- acute gouty arthritis
- polyarticular gouty arthritis
- chronic tophaceous gout
What is another name for chronic tophaceous gout?
lumpy bumpy joint disease
What food and beverages are high in purines and can predispose an individual to gout?
- red meat
- red wine
- beer
- aged cheeses
Gout is primarily a disease of ____ structures
soft tissue
(does not have to be in jts.)
A patient with recurring acute gouty arthritis who continues to eat copious amounts of red wine and aged cheeses is likely to develop ____
polyarticular gouty arthritis
What causes the “lumpy bumpy” appearance of chronic gout?
tophi
What are the radiographic characteristics of gout?
- marginal erosions (“overhanging margins”)
- periarticular erosions
- intraosseous erosions
- corticated erosions
- soft tissue swelling
What causes the radiographic appearance of periarticular erosions in gout?
crystals deposit into periarticular soft tissues –> inflammation erodes bone
What causes “overhanging margin” sign in gout?
bone regrowth of marginal bone during remissions
What causes corticated erosions in gout?
longer remission periods of gout allow for thin cortical bone to begin forming around erosions
What is the average radiographic latent period for gout?
7 years
What would you include on your list of differential diagnoses for extensive soft tissue swelling around the elbow?
- Olecranon bursitis (“water on the elbow”)
- septic bursitis
- gout (in olecranon bursa)
What are the treatment options for gout?
- Diet (less purines, ^H2O, bing cherry juice)
- NSAIDs/corticosteroids (short term)
Refer to rheumatology:
- colchicine (for recurrent attacks)
- allopurinol (inhibits xanthine oxidase)
- uloric
