Gout and pseudogout Flashcards
What is gout?
Inflammatory arthritis caused by deposition of sodium urate crystals into joints in hyperuricaemia
What are risk factors for gout?
Excessive alcohol intake, high protein diet, diuretic use, diabetes mellitus, obesity, high cell turnover conditions (haemolytic anaemia, malignancies)
How does gout present? Describe chronic tophaceous gout?
Single tender, red, swollen joint (can be multiple)
Maximum intensity after 6-12 hours
Commonly 1st MTP joint (Podagra)
Episodes last days to weeks
Chronic tophaceous gout: Irregular firm nodules due to large crystals with chalky appearance underneath the skin
What do investigations show in gout?
High serum uric acid level (can fall in acute episode)
Polarising microscopy of synovial fluid shows negatively birefringement rhomboid shaped crystals and raised WCC
X ray can be used for chronic gout, shows punched out lesions in bone
How is gout managed?
1) Treat cause
2) Acute–> NSAIDs, colchicine, corticosteroid intra articular injection
3) Prophylaxis–> Allopurinol
How should allopurinol be given in gout?
Do not start during acute attack
Start at least 2w after symptoms disappear, continue through future attacks
Increase dose every 2-4 weeks until uric acid is within the target range (<300 micro moles/litre)
When starting allopurinol and increasing dose patients are at increased risk of a flare up, can prevent with NSAIDs and colchicine
What is pseudogout?
Deposition of calcium pyrophosphate crystals in the joints
What are the symptoms of pseudogout?
Often asymptomatic, affects knees, wrists, shoulder, ankles, elbows, hands
Risk factors fo pseudogout?
Osteoarthritis, hyperparathyroidism, joint trauma, haemochromatosis, family history, hypophosphataemia
What do investigations for pseudogout show?
Under polarising microscopy positively birefringement rhomboid shaped crystals are seen
What is the management of pseudogout?
Asymptomatic: No treatment
Symptomatic: NSAIDs, colchicine, intra-articular steroid
No long term preventative treatment, long term colchicine can be used to prevent flare-ups
