Abscess, boil, furuncle, carbuncle, pimple and pustule all denote a localized swollen area of infection containing pus.
Abscess is the most general term, applying to a collection of pus surrounded by inflammation whether in the skin or in the substance of a part or organ and whether discharging through an opening or fistula or being gradually reabsorbed.
- An abscess at the root of a tooth.
- A line of small abscesses where his belt had chafed him.
Boil and furuncle both mean a swollen painful nodule in the skin caused by bacteria that enter skin glands or hair follicles and set up a purulent infection which terminates by rupture of the skin and discharge of a core of pus and broken-down tissue cells.
Though boil is commoner in general use, furuncle is often preferred in medical communication.
A carbuncle is a large and severe boil that occurs especially on the back of the neck, is often accompanied by fever, and ultimately discharges through several openings.
A pimple or pustule is a small superficial puscontaining elevation of the skin that usually subsides without rupturing; more specifically pimple is used of the typical lesions characterizing acne while pustule implies no specific syndrome.