Gout usually manifests itself in the lower extremities. It is caused by hyperuricemia, or excess uric acid in the blood.
Gout, also known as gouty arthritis, is a disease known since biblical times. According to rheumatology specialists, it is caused by the deposit of uric acid microcrystals in the joints and affects those patients who present hyperuricemia, that is, excess uric acid in the blood (a concentration higher than 7 mg/dl, the point of solubility of uric acid at body temperature).
It is worth mentioning that uric acid is a product of the degradation of purines, a component present in the nucleus of cells. Any pathology that produces a deficit in the renal elimination of uric acid or an excess of its production can cause it to be deposited in the form of microcrystals in the joints. What causes this process is an inflammatory stimulus at the level of the articular synovial membrane, triggering arthritis.
Causes of gout
The cause of gout is hyperuricemia, although not all people who suffer from hyperuricemia will have gout. There are two fundamental causes for hyperuricemia to occur: the existence of a deficit in the elimination of uric acid at the renal level, or an excess of its production. The most frequent cause (90% of cases) is the elimination deficit, and usually has a genetic component. However, certain factors may contribute to the onset of gout:
- diet rich in purines (foods such as red meats, seafood and sausages).
- alcohol consumption (decreases uric acid elimination)
- concomitant diseases that alter endogenous metabolism (renal insufficiency, psoriasis, blood dyscrasias involving alterations in the white and red blood cell count, etc.)
- some medications
Symptoms and treatments of gout
Characteristically gout manifests itself with episodes of:
- severe joint pain (arthritis) with swelling
- redness
- increased local temperature
- increased sensitivity to touch
In addition, it usually presents in the form of single arthritis (monoarthritis) in joints of the lower extremities (mainly the big toe or ankle).
Occasionally accumulations of uric acid may form in the soft tissues, in the form of hard nodules (“tophi”) which can sometimes open up and spill their contents to the outside.
Today there are very effective treatments to reduce hyperuricemia that allow the dissolution of uric acid crystals, so that arthritis flare-ups and soft tissue deposits do not occur.
Who is affected by gout?
Gout usually affects adult patients. However, there are rare hereditary diseases included in the group of inborn errors of metabolism that can cause gout in childhood. One example is Lesch-Nyhan syndrome, caused by a deficiency of an enzyme (hypoxanthine-guanine-guanine phosphoribosyltransferase), which regulates purine metabolism. This syndrome, in addition to infantile gout, is associated with neurological disorders and cognitive dysfunction.