hereditary metabolic disorder characterized by recurrent acute attacks of severe inflammation in one or more of the joints (joint) of the extremities. Gout results from the deposition, in and around the joints, of uric acid salts, which are excessive throughout the body in persons with the disorder. Uric acid is the metabolic end product of purines (purine) and normally is steadily excreted into the urine. The enzyme defect that leads to abnormal concentration of the substance in the body is unknown. Gout accounts for at least 5 percent of all cases of arthritis. It is uncommon, however, in women; the male-female ratio is 20:1. Pseudogout (chondrocalcinosis) is a similar condition caused by deposits of calcium pyrophospate crystals in the joints.

Although gout is probably inborn, the initial attack of acute joint inflammation, or gouty arthritis, usually does not appear until middle age. Any peripheral joint may be affected, but for some reason the joint at the base of the big toe is especially susceptible. Symptoms include redness of the skin and extreme tenderness, warmth, and pain of the affected joints. An attack, even when untreated, may subside in a week or two. Attacks may come and go without apparent reason, but there are a number of precipitating factors, including acute infection, emotional upset, diuresis, surgery, trauma, and the administration of certain medications. Precipitation of uric acid in the joint cartilage precedes the first attack. In some cases, continued deposition of uric acid salts may cause knobby deformities (tophi) and may also occur in cartilage that is not associated with the joints, such as the rim of the ear.

Treatment for an acute attack of gout includes the administration of nonsteroidal anti-inflammatory drugs (NSAIDs) such as indomethacin and naproxen. Corticosteroids may also be injected into the affected joint to reduce inflammation. A medication called colchicine may be administered if NSAIDs and corticosteroids are not effective. Medications such as allopurinol and probenecid, which inhibit the synthesis of uric acid in the body, are used to treat recurrent acute attacks.