Crystal Arthropathies Flashcards
How does gout present?
Acute monoarthropathy with severe joint inflammation
>50% occur at the metatarsophalangeal joint of big toe
Can be polyarticular. Caused by deposition of monosodium urate crystals in and near joints.
Associated with raised plasma urate
What can precipitate attacks of gout?
Precipitated by trauma, surgery, starvation, infection or diuretics
Causes of gout are split into ‘reduced urate excretion’ and ‘excess urate production’. What are the ‘reduced urate excretion’ causes?
Elderly Men Post-menopausal females Impaired renal function Hypertension Metabolic syndrome Diuretics Antihypertensives Aspirin
Causes of gout are split into ‘reduced urate excretion’ and ‘excess urate production’. What are the ‘excess urate production’ causes?
Dietary Genetic disorders Myelo- and lymphoproliferative disorders Psoriasis Tumour lysis syndrome
What are the investigations used for gout?
Polarised light microscopy for synovial fluid shows negatively bi-refringent urate crystals (needle shaped)
Late sign: well defined ‘punched out’ erosions are seen in juxta articular bone.
What is the treatment of acute gout?
High dose NSAID or colchicine 500microg BD
Rest and elevate joint
Ice packs are used
How do you prevent gout from happening?
Lose weight
Avoid prolonged fasts
Alcohol excess
Low dose aspirin
Use allopurinol and titrate from 100mg/24h, increasing every 4 weeks. Start allopurinol if >1 attack in 12m, tophi, or renal stones.
What happens in pseudogout (calcium pyrophosphate deposition)
Acute monoarthropathy, usually of larger joints in elderly people. Usually spontaneous
Polarised light microscopy of synovial fluid shows positively bi-refringent crystals (rhomboid shaped)
Associated with soft tissue calcium deposition on X-Ray
What is the management of calcium pyrophosphate deposition?
Acute attacks: cool packs, rest, aspiration, intra articular steroids
NSAIDs and colchicine may prevent acute attacks
