Gout is a disease known since ancient times. It is characterized by sudden episodes of intense pain, swelling, redness, great sensitivity to touch and increased local temperature, in one or more joints due to the deposit of urate salts inside them.
The inflammation of the joints in gout is due to the fact that microcrystals of a salt of uric acid (monosodium urate monohydrate) are formed inside. Attacks of inflammation are a consequence of the presence of these crystals in the joint, and never occur in their absence. In order for urate crystals to form, it is necessary that the levels of uric acid in the blood are high, which is known as hyperuricemia; in any case, although hyperuricemia is common (7% of the population has it), only a minority of people who have it end up forming crystals and suffering from gout.
Gout essentially produces joint inflammation, almost always in the form of acute arthritis of a single joint; that is, a joint goes from being asymptomatic to intensely swollen within a few hours (which is due to the fact that its cavity is filled with synovial fluid forming an effusion), its surface may turn red, and it almost always becomes intensely painful and its function is made difficult by the pain. Sometimes the inflammation can be less intense and the discomfort more bearable. The joints that can suffer gout attacks are various, but the most common are the base of the big toe (what are called gout attacks), the back of the foot, ankle, knee, wrist or some joint of the toes the hand. The synovial bursa in the elbow, or the bursa where the Achilles tendon attaches to the heel, can also become inflamed.
The presence of urate crystals is necessary for the joints to become inflamed. These crystals are identified, by means of a microscope, in the synovial fluid extracted from inflamed joints during gout attacks, and allow a precise diagnosis of the disease; moreover, the crystals can also be easily identified in the material obtained from a tofu or in the fluid of asymptomatic joints that have previously been inflamed.
Gout is a disease with a currently very effective treatment. It must be approached as two independent problems: the treatment of the acute attack of gout and the treatment of the increase of uric acid in the blood (hyperuricemia).
Uric acid crystals (blue color) in synovial fluid under a polarized light microscope.
