Abscess

Abscess, localized accumulation of pus, usually representing a response of the body to bacterial infection. The bacteria enter the skin via a natural opening or small cut, and they can pass into the intestinal mucous membrane or the respiratory system and be swept by the bloodstream to various organs of the body. The immune, or defense, system of the body possesses 2 mechanisms for destroying the penetrating bacteria: the leukocytes (white blood cells) and antibodies. If these defense mechanisms succumb to the bacteria, an abscess forms: The bacteria destroy a large number of cells, causing tissue death and the formation of an ulcer, which forms a pussy mass. Fortunately, the tissue is usually capable of stopping the destructive work of the bacteria, forming a barrier to the spread of the bacteria by building a wall of cells and connective tissue. Such an abscess may drain spontaneously; otherwise it should be incised.

See also: Carbuncle.