abscess

a localized purulent inflammation of tissues, involving their dissolution and the formation of a pus-containing cavity.

Abscesses may develop in the subcutaneous cellular tissue, in muscles, bones, and so forth, as well as in organs (such as the liver, lungs, spleen, and brain) or between them (interintestinal abscesses, subphrenic abscesses, and so on). Abscesses may appear either independently or as a complication in other diseases—for instance, pneumonia, trauma, etc. They develop as a result of the penetration of pyogenic microbes into the organism through lesions of the skin or the mucous membranes or as a result of importation of pathogenic agents from other purulent foci through the blood and lymph vessels. The microbes that have entered the tissues cause inflammation and subsequent necrosis of a section of tissue or organ. The abscess is surrounded by a zone of inflammation. The organism’s defense reaction is manifested in the formation of a capsule separating the abscess from healthy tissue. The volume of pus in the cavity of an abscess may reach several liters.

The manifestations of abscesses depend on their location, depth, and stage of development. Abscesses located close to the skin or to a mucous membrane cause their reddening, an increase in local and overall temperature, swelling, and fluctuation—a sensation of impulse transmission through a liquid from one wall to the other. When an abscess is deep, the function of the organ in which it is embedded is disturbed, body temperature rises, and pain sets in. The number of leukocytes in the blood and the erythrocyte sedimentation rate (ESR) increase. If the capsule becomes thin, the abscess will open up by itself through the skin or into the bronchial or intestinal lumen, etc. Serious complications develop when abscesses break open into the pleural or abdominal cavity. Abscesses are treated by surgery.