[Gout].

In the presence of a clinical acute monoarthritis, a differential diagnosis has to be made between septic arthritis, gout and diffuse chondrocalcinosis. Gout comes from a purine nucleotide metabolism disorder leading to serum urate level elevation. This hyperuricemia can lead to the deposition of monosodium urate crystals in the joints, causing acute attacks. After long-term evolution, others tissues as the kidneys can be involved: it is chronic gout. The definite diagnosis is based on the presence of monosodium urate crystals in the joint fluid. The diagnosis of gout should prompt a search for associated medical conditions that may affect both urate levels and longevity. These include alcoholism, various nephropathies, myeloproliferative disorders, and hypertension.