the accumulation of pus in a closed body cavity or in a hollow organ if the outlet for the pus is blocked by a concrement or inflammatory infiltrate. Empyema may develop after purulent inflammation of the walls of a cavity or organ caused by shifting of the inflammatory process from the nearest organ, for example, from bone to the walls of a joint cavity in osteomyelitis. It also occurs after direct penetration of the infection into a cavity upon injury to its wall, for example, after rupture of a pulmonary abscess into the pleural cavity. The symptoms of empyema vary depending on whether the condition is acute or chronic and on the site of the infection. They may include a high fever, intoxication, pain, and change in the blood composition.
Treatment may require removal of the affected organ, for example, in suppurative appendicitis and suppurative cholecystitis. In some cases the purulent cavity is opened, pus is removed and the cavity is drained, for example, in suppurative pleurisy (thoracic empyema) or suppurative arthritis.