Crystal Arthropathies Flashcards
What are the 3 categories of crystal arthropathies
Gout, pseudo-gout and hydroxyapatite
What is gout
deposition of monosodium urate cyrstals, inflammatory arthritis
What do gout crystals look like
Needle shaped
Why is gout very rare in women before the menopause
Oestrogen is protective
Who does gout affect more
Men more than women 4:1
What are the two causes of hyperuricaemia
Increased urate production and reduced urate excretion
What are the main causes of increased urate production
Alcohol, high dietary purine intake (red meat, seafood, corn syrup - processed foods), psoriasis, haemolytic disorders
What are the main causes of reduced urate excretion
Chronic renal impairment, volume depletion (eg heart failure), severe hypothyroidism, diuretics, cytotoxics
What is the process of uric acid metabolism
Purines, hypoxanthine, xanthine, plasma urate then to urine, uric acid
Does everyone with hyperuricaemia get gout?
no
When can acute gout come on
Can happen overnight
Where does acute gout usually present
in one joint, commonly 1st MDP joint in foot - also can be wrists, elbows, ankles
When does acute gout usually settle
Settles in 10 days without treatment, but settles in 3days with treatment
How is chronic tophaceous gout caused
if acute attacks of gout are allowed, tophi develop - usually often diuretic associated
Why may be serum uric acid be normal during acute attack
As the uric acid is in the joint affected, not in the serum!
