The diagnosis is confirmed by laboratory finding of uric acid crystals in fluid taken from the affected joint. Together, these factors might explain why the big toe, heel, instep, and Achilles tendon are among the places that gout attacks first. Other targets, especially in untreated patients who have recurrent attacks of gout, are the knee, elbow, wrist, fingers and, less often, the shoulder, pelvis, spine, and internal organs. Gout is classified as a form of arthritis because it is initially and predominantly a disease of the joints. Infection or trauma to the affected area can mimic gout and mislead both patients and health professionals.
Accurate diagnosis is essential for appropriate treatment.
Without treatment, an initial acute attack of gout will run its painful course within several days or a few weeks, by which time all outward evidence of the disease disappears. Subsequent attacks, however, are likely to be more frequent, more severe, and more destructive to joints and other tissue unless the problem is treated. Over time, uric acid crystals accumulate in the body, causing gritty, chalky deposits called tophi that are sometimes visible under the skin, particularly around joints and in the edges of the ears. Tophi may also form inside bone near the joints, in the kidneys, and in other organs and tissues, causing permanent damage. Advances in treatment, fortunately, have made this kind of chronic gout extremely rare.