Abscess

A localized collection of pus in any body part that results from invasion of a pyogenic bacterium or other pathogen is called an abscess.  Staphylococcus aureus is a common cause. The abscess is surrounded by a membrane of variable strength created by macrophages, fibrin, and granulation tissue. Abscesses can disrupt function in adjacent tissues and can be life threatening if the swelling interferes with breathing or vital organ function.