National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS). Questions and Answers About Gout. Bethesda, MD: NIAMS, 2002. NIH Publication No. 02-5027. 〈www.niams.nih.gov/hi/topics/gout/gout/htm〉.
[ gowt ]
a form of arthritis in which uric acid appears in excessive quantities in the blood and may be deposited in the joints and other tissues. During an acute attack there is swelling, inflammation, and extreme pain in a joint, frequently that of the big toe. After several years of attacks, the chronic form of the disease may set in, permanently damaging and deforming joints and destroying cells of the kidney. Most cases occur in men and the first attack rarely occurs before the age of 30.
Causes. The causes of gout include excessive production of uric acid, as an inherited condition or as a side effect of chemotherapy for tumors, and impairment of clearance due to the antihypertensive agent hydrochlorothiazide or to low-dose aspirin .
Acute Gout. This form usually strikes without warning. The affected joint, which in 70 per cent of cases is that of the big toe, becomes swollen, inflamed, and very painful. The first attack may follow an operation, infection,
or minor irritation such as tight shoes, or it may have no apparent cause. The patient may have a headache or fever, and often cannot walk because of the pain.
A metabolic disorder characterised by increased uric acid in the blood and joints, resulting in recurring painful arthritis and renal dysfunction with deposits of uric acid in the urinary tract, which in some cases is caused by either of two X-linked enzymes.
One-half of cases present with the classic “podagra” which affects the metatarsophalangeal joint; up to 90% suffer podagra at some time during their disease. With time, the attacks become polyarticular. Gouty tophi accumulate on the ears and over joints. Patients with gout are at high risk of forming kidney stones, which, in extreme cases, can cause renal failure.
Alcoholism, hereditary defect of hypoxanthine-guanine phosphoribosyl transferase (HG-PRT), phosphoribosylpyrophosphate synthetase superactivity, obesity, hypertension, renal dysfunction, drugs; family history of gout is present in about half of cases.
Increased uric acid, often ≥ 410 µmol/L–US: 7.0 mg/ml, a level found in a significant minority of men (90% of gout occurs in men).