Crystal Arthropathies Flashcards
What is the pathophysiology of gout?
Hyperuricaemia –> uric acid crystals precipitate in joint –> inflammation
What are some causes of gout?
Renal under secretion: renal failure, diuretics
Excess intake: alcohol, red meat, seafood
What might precipitation of uric acid in a joint be triggered by?
Dehydration
Trauma
Surgery
Which joints are most commonly affected by gout?
1st MTP > ankle > knee
Describe the clinical features and course of acute gout?
Abrupt onset, often overnight
Intensely painful, hot, red joint
Serum uric acid may be normal
Settles in about 10 days without treatment, 3 days with treatment
What is chronic tophaceous gout?
Chronic joint inflammation, high serum uric acid
Often diuretic associated
–> joint erosion/destruction
What might been seen on examination of a joint with chronic tophaceous gout?
Tophi –> painless white accumulations of uric acid in soft tissues which occasionally erupt through skin
Which investigations should be done for gout?
Inflammatory markers - raised
Serum uric acid - may be normal if acute
Sample synovial fluid - polarising microscopy shows needle shaped negatively birefringent crystals
Renal function - cause or effect
What is the treatment for acute gout?
NSAIDS, steroids and opiates
Colchicine if cannot tolerate NSAIDs
What is the treatment for chronic gout?
Allopurinol or Febuxostat
–> start 2-4 weeks after acute attack (can potentiate a further flare)
What is pseudogout cause by?
Calcium pyrophosphate crystals
What is chondrocalcinosis?
When calcium pyrophosphate deposition occurs in cartilage and other soft tissues in the absence of acute inflammation
What is Calcium Pyrophosphate Deposition Disease (CPDD)?
Umbrella term including both pseudo gout + chondrocalcinosis
Which joints tend to be affected by CPDD?
Knee
Wrist
Ankle
Which conditions are associated with CPDD?
Hyperparathyroidism Hypothyroidism Renal osteodystrophy Haemochromatosis Wilson's disease
