Purulence

Purulence is the presence of pus within a tissue or discharge, reflecting a suppurative inflammatory process. The noun describes the material itself; purulent is an adjective used for pus-containing exudate or infections. The term purulent is often used interchangeably with suppurative in clinical practice. Etymology traces to Latin purulentus, meaning full of pus.

Pus is a complex inflammatory product rich in neutrophils, dead cells, bacteria, and protein-rich fluid. It forms when bacterial infection triggers rapid recruitment of neutrophils, which kill microbes but also release enzymes that degrade tissue. When the infection is localized, pus accumulates and may create an abscess.

Clinical features vary by site but commonly include purulent discharge or exudate that is thick, opaque, and yellow to green in color; it may be accompanied by pain, swelling, warmth, and a foul odor. In the respiratory tract, purulent sputum; in wounds, a purulent drainage; in the ear or sinuses, purulent fluid.

Diagnosis is clinical, supported by the appearance of pus. Microbiological culture can identify pathogens; imaging may be used to assess deeper collections or abscess formation. Purulence can indicate infection severity and the need for drainage or antibiotics, though management depends on site, extent, and patient factors.

Management focuses on source control, wound care, and, when indicated, antimicrobial therapy. Drainage of purulent collections is often essential. Education and monitoring for systemic infection signs—fever, malaise, or spreading redness—are important.