Gout: predisposing factors
Gout is a form of microcrystal synovitis caused by the deposition of monosodium urate monohydrate in the synovium. It is caused by chronic hyperuricaemia (uric acid > 0.45 mmol/l)
Decreased excretion of uric acid
Increased production of uric acid
Lesch-Nyhan syndrome
*aspirin in a dose of 75-150mg is not thought to have a significant effect on plasma urate levels - the British Society for Rheumatology recommend it should be continued if required for cardiovascular prophylaxis
Decreased excretion of uric acid
- drugs*: diuretics
- chronic kidney disease
- lead toxicity
Increased production of uric acid
- myeloproliferative/lymphoproliferative disorder
- cytotoxic drugs
- severe psoriasis
Lesch-Nyhan syndrome
- hypoxanthine-guanine phosphoribosyl transferase (HGPRTase) deficiency
- x-linked recessive therefore only seen in boys
- features: gout, renal failure, neurological deficits, learning difficulties, self-mutilation
*aspirin in a dose of 75-150mg is not thought to have a significant effect on plasma urate levels - the British Society for Rheumatology recommend it should be continued if required for cardiovascular prophylaxis