Gout Flashcards
What is gout?
A crystal athropathy characterised by deposition of urate crystals within a joint
Causes of gout
High serum uric acid levels = hyperuricaemia
What is uric acid?
The final compound in the breakdown of purines in DNA metabolism (adenine and guanine)
How is hyperuricaemia caused?
Renal underexcretion
Excessive alcohol intake
Red meat and seafood consumption
Genetic predisposition
What triggers the precipitation of uric acid crystals in joints?
Dehydration
Trauma
Surgery
Where is the classic site of gout?
The first metatarsophalangeal joint (MCP) = Podagra
Presentation of gout
Intensely painful joint Hot joint Swollen joint May mimic septic arthritis Symptoms usually last 7-10 days then resolve
What are gouty tophi?
Painless, white accumulations of uric acid in soft tissues. These can occasionally erupt through the skin.
Diagnostic test for gout
Synovial fluid analysis with polarised microscopy. Uric acid crystals are needle-shaped and display negative birefringence (change from yellow to blue when lines across the direction of polarisation)
Treatment of gout
NSAIDs
Corticosteroids
Opioid analgesics
Colchicine for patients who cannot tolerate NSAIDs
Allopurinol to prevent attacks but should not be started until an acute attack has settled as they can potentiate a future flare
Define pseudogout
Another crystal arthropathy causing an acute arthritis, but in contrast to gout, is caused by calcium pyrophosphate crystals.
Define chondrocalcinosis
Calcium pyrophosphate deposition in cartilage and other soft tissues in the absence of acute inflammation.
Where does calcium pyrophosphate deposition disease tend to affect?
Knee, wrist and ankle
Causes of calcium pyrophosphate deposition disease
Hyperparathyroidism Hypothyroidism Renal osteodystrophy Haemochromatosis Wilson's disease OA
Treatment of calcium pyrophosphate deposition disease
Acute attacks: NSAIDS, corticosteroids and colchicine
No prophylactic medications
