Pus
Pus is a thick fluid that forms in response to infection, primarily caused by bacteria such as Staphylococcus aureus. It consists of white blood cells, dead bacteria, and cellular debris, accumulating at the site of inflammation. Pus can manifest in various parts of the body, such as skin infections like pimples or abscesses, and deeper infections affecting organs like the brain, liver, or kidneys. Symptoms associated with pus-producing infections may range from localized swelling and tenderness to systemic signs like fever, depending on the severity and location of the infection.
While the presence of pus itself may not require treatment, it is crucial to identify the underlying cause. For minor superficial infections, maintaining hygiene and applying topical treatments can be effective. In more severe cases, antibiotics may be necessary, and surgical interventions might be required to drain the pus and facilitate healing. Understanding the nature of pus and its implications can help individuals make informed decisions regarding their health and seek appropriate medical advice when needed.
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Subject Terms
Pus
Also known as: Exudate
Anatomy or system affected: All
Definition: A thick, white, or yellow fluid expressed from a site of infection containing white blood cells
Causes and Symptoms
Pus is formed within an inflamed, infected area of the body in response to the presence of bacteria, most commonly Staphylococcus aureus. White blood cells are attracted to the infected area and release chemicals that destroy the bacteria. Consequently, the region begins to fill with these white blood cells along with cellular debris and dead bacteria. This fluid is what one typically thinks of as pus.
Any area of the body can become infected and lead to the inflammatory cascade that produces pus. This process may be visible just underneath the skin in the case of pus produced by a skin infection, such as a pimple or superficial abscess (boil). Pus may also be found in deeper, internal regions of the body when other organs are infected. Pus may be involved in the body’s response to sinusitis, ear infections, and pneumonia, as well as infection with abscess formation in the brain, liver, and kidneys. When an infection produces pus, it may also be referred to as a purulent, suppurative, or pyogenic infection.
Symptoms of an infection that produces pus vary. Some infections may be completely asymptomatic, while others may be accompanied by fever and localized swelling or tenderness. In the case of a superficial process, the area that surrounds the pus may be red, warm, and firm in response to the inflammation taking place within the infected site. In deeper infections, the symptoms may be related to the organ that is infected, such as headache and confusion with a brain abscess or back pain and painful urination with a kidney abscess.
Treatment and Therapy
The presence of pus itself does not necessarily require treatment. When pus is present, it is important to find the source and determine what process is creating it. This underlying process may need treatment, or it may resolve on its own without intervention. In the case of superficial pimples or abscesses, one is advised to maintain good hygiene and not disturb the wound. It may also be helpful to clean the area with a mild cleanser and apply a topical antibiotic and bandage. Hot compresses may also be used to soften the overlying skin to bring the underlying pus to the surface for drainage. If the infection persists, antibiotics may be required to fight the underlying bacterial process, or incision and drainage of the area to release the pus may be necessary.
In the case of deeper infections involving pus, antibiotics are often required. Surgical drainage may also be necessary to drain the pus and promote the healing of the infection.
Bibliography
Auerbach, Paul. “Minor Medical Problems.” In Medicine for the Outdoors: The Essential Guide to Emergency Medical Procedures and First Aid, edited by Paul Auerbach. Guilford, Conn.: Lyons Press, 2003.
Dugdale, David C., III. "Exudate." MedlinePlus, May 22, 2011.
Masoff, Joy, and Terry Sirrell, eds. Oh, Yuck! The Encyclopedia of Everything Nasty. New York: Workman Publishing, 2000.
Pier, Gerald, and Jeffrey Lyczak, eds. Immunology, Infection, and Immunity. Washington, D.C.: ASM Press, 2004.
Seladi, Jill, and Donna Christiano. “Pus: Causes, Locations, Symptoms, Treatment, and Prevention.” Healthline, 7 Feb. 2018, www.healthline.com/health/pus. Accessed 21 July 2023.