Gout Flashcards
Which joint does gout most commonly affect?
More than 50% of cases occur in the metatarsophalangeal joint of the big toe (podagra)
Where else can it affect?
Ankle, foot, small joints of the hand, knee, elbow or wrist
Can it be polyarticular or not?
It can be polyarticular
What is gout?
Deposition of mono sodium u rate crystal in the synovium causing acute inflammation
Is it more com one in women or men?
Men (4:1)
How does this mono sodium urate crystal deposition occur?
Hyper uricaemia occurs, 10-20% of patients with this develop gout
What factors increase the levels of uric acid in the plasma?
Obesity, huh alcohol, hypertension, renal impairment, long term diuretic use
What events can precipitate attacks of gout?
Trauma, surgery, starvation, infection, diuretic use
What develops long term due to gout?
Gout trophi form in the pinna, tendons and joints Renal disease (stones/interstitial nephritis)
What are the main differentials to consider?
Septic arthritis, Palindromic RA, CPPD (pseudogout), haemoarthrosis
Gout is associated with what diseases?
Cardiovascular disease, hypertension, diabetes, diabetes, chronic renal failure
What investigations would you do?
Polarised light microscopy, serum urate, FBCs, XR
Under polarised light microscopy what characteristic do urate crystals have? (That calcium pyro phosphate are the opposite of)
Monosodium urate crystals in synovial fluid are negatively bifringent
What might XR show?
Soft tissue inflammation. Juxta-articular erosions later, everything else may look normal, no loss of joint space till very late
Why is serum urate not that useful?
As urate levels may very well be normal and cannot exclude gout if normal
What is the treatment of gout?
High dose NSAIDS or coxib (COX-2 inhibitor)
Elevate and rest joint
Should clear in 3-5 days
What would you give if CI to NSAIDS and coxib (peptic ulcer, heart failure, anticoagulant ion)
Colchicine
What conservative measures help to prevent gout?
Lose weight, exercise, avoid prolonged fasts, stop drinking XS, avoid purine rich meats and low dose aspirin which increase plasma urate
When would you start the patient on prophylactics?
If they have had more than 1 attack in the past 12 months
What drug would you give to prevent gout?
Allopurinol (100mg/24hrs tut rate up to 300mg/8hrs)
What might allopurinol trigger?
An acute attack of gout
Despite attacks what should you avoid?
Stopping allopurinol once an established treatment
What are the SEs of allopurinol?
Rash, lowered WCC, fever
What can be used if CI to allopurinol?
Febuxostat
What is the typical presentation of gout?
Acute monoarthropathy with severe joint inflammation
What enzyme is responsible for converting purines into uric acid?
Xanthine oxidase
What proportion is caused by impaired excretion compared to increased production of uric acid?
90/10
