birefringent crystals (negative)
Gout is a painful and potentially disabling form of inflammatory arthritis that has been recognized since ancient times
It is a disorder of purine metabolism characterized by hyperuricaemia and the deposition of monosodium urate crystals in articular or peri-articular tissues and in the renal tract (1,2).
- uric acid is the breakdown product of purine residues of nucleic acid and two thirds of it are excreted via the kidney; the remainder, via the gut
- the likelihood of crystal formation increases as the level of uric acid increases (most often results from impaired fractional renal clearance of urate rather than from excessive production), and at low temperature. This helps to explain the peripheral distribution of gout (2)
- not all patients with hyperuricaemia have gout.
- (1) Doherty M. New insights into the epidemiology of gout. Rheumatology (Oxford). 2009;48 Suppl 2:ii2-ii8.
- (2) Jordan KM et al. British Society for Rheumatology and British Health Professionals in Rheumatology guideline for the management of gout. Rheumatology (Oxford). 2007;46(8):1372-4
Last reviewed 07/2021