Abscessation

DEFINITION
An abscess is a localized collection of purulent exudate contained within a cavity.

PATHOPHYSIOLOGY
Bacteria are often inoculated under the skin via a puncture wound; the wound surface then seals.
When bacteria and/or foreign objects persist in the tissue, purulent exudate forms and collects.
Accumulation of purulent exudate—if not quickly resorbed or discharged to an external surface, stimulates formation of a fibrous capsule; may eventually lead to abscess rupture
Prolonged delay of evacuation—formation of a fibrous abscess wall; to heal, the cavity must be filled with granulation tissue from which the causative agent may not be totally eliminated; may lead to chronic or intermittent discharge of exudate from a draining sinus tract