Crystal Arthropathies Flashcards
How does gout present?
What causes gout?
- Monosodium rate crystal deposition
- Reduced clearance of the crystals
- Increased production of the crystals
- Attacks may be precipitated by:
- Trauma
- Surgery
- Infection
- Starvation
- Diuretics
What plasma change i gout associated with?
What are some long term complications of gout?
- Urate crystal deposition can lead to formation of tophi
- Tophi which are…
- It can also lead to renal disease
- Stones
- Interstitial nephritis
What are tophi?
- Tophi are deposit of uric acid crystals, in the form of monosodium urate crystals, in people with longstanding hyperuricemia (high levels of uric acid in the blood).
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What are the risk factors of gout caused by reduced urate excretion?
What are the risk factors of gout caused by excess urate production?
- Dietary
- Excess alcohol intake
- Sweeteners
- Red meat
- Seafood
- Genetic disorders
- Drugs
- Alcohol
- Warfarin
- Cytotoxics
- Myeloproliferatice disorders
- Lymphoproliferative disorders
- Psoriasis
- Tumour-lysis syndrome
What diseases are associated with gout?
- Diabetes mellitus
- Cardiovascular disease
- Hypertension
- Chronic renal disease
- Gout is an independent risk factor for cardiovascular and renal disease
- These diseases should be screened for and treated
What tests should be carried out to investigate gout?
- Polarised light microscopy of synovial fluid shows biferegent urate crystals
- Serum urate is usually high but may be normal
- Imaging
- Radiographs only show soft tissue swelling at the early days
- Well-defined punched out erosions are seen in juxta-articular bones
- Joint spaces are preserved until late
How is gout treated?
- High dose NSAIDs
- Colchine
- If NSAIDs are contraindicated
- SLower to work but effective
- Both are contrainidcated in renal disease
- Steroids
- Rest and elevate
- Ice packs
- Bed cages
How is gout prevented?
- Lose weight
- Avoid:
- Prolonged starvation/fasting
- Alcohol excess
- Purine rich meats
- Low dose aspirin
- Prophylaxis (start if patient has had >1 attacks in a year
- Allopurinol
- decreases the attacks and prevents damage caused by crystal deposition
- titrate and increase dose every 4 weeks until plasma urate decreases
- Febuxostat
- Used if allopurionol is contraindicated or not tolerated
- Allopurinol
What are the side effects of allopurinol?
- Rash
- Fever
- Reduced WCC
- It may trigger an attack so wait 3 weeks after an acute episode and cover with regular NSAID or colchne
- Avoid stopping allopurionol in acute attacks once established
How does febuxostat work and what are the side effects?
- It decreases uric acid by inhibiting xanthine oxidase
- It is more effective at reducing serum urate than allopurinol (number of acute attacks the same)
- Raised LFTS
What is acute calcium pyrophosphate deposition (CPPD) arthritis?
- Acute monoarthropathy usually of larger joints in elderly
- It is usually spontaneous but can be provoked by illness, surgery or trauma
What is chronic calcium pyrophosphate deposition (CPPD) arthritis?
Inflammatory RA-like (symmetrical) polyarthritis and synovitis
What is this?
Gout
What is this?
Tophi
Describe the appearance of gout under polarised light
- Needle shaped monosodium urate crystals
- Negatively birefringent
Describe the appearance of CPPD under polarised light
- Rhomboid shaped calcium pyrophosphate dihydrate crystals in pseudogout
- Positively birefringent in polarised light
