An abscess is a collection of pus in any part of the body that is surrounded by swelling and inflammation. An abscess may develop, enlarge, or subside, depending upon the degree of infection by microorganisms, such as bacteria. Abscesses may develop in any organ and in the soft tissues beneath the skin in any area.
Common sites of abscesses include the breasts, gums, and peri-rectal area. Less common sites include the brain and liver. Common sites for abscesses under the skin include the armpit and the groin. These two areas have a large number of lymph glands, which are responsible for fighting infection.
Boil: A boil, also referred to as a skin abscess, is a localized infection deep in the skin. A boil generally starts as a reddened, tender area. Over time, the area becomes firm and hard. Eventually, the center of the abscess softens and becomes filled with infection-fighting white blood cells that the body sends from the blood stream to stop the infection. This collection of white blood cells, bacteria, and proteins is known as pus. Finally, the pus forms a head, which can be drained out through the surface of the skin using pressure or surgical methods. Most boils run their course within four to ten days.
Furuncle or carbuncle: Furuncles or carbuncles are abscesses in the skin caused by the bacterium Staphylococcus aureus. A furuncle can have one or more openings onto the skin and may be associated with a fever or chills.
Cystic acne: Cystic acne is a type of abscess that is formed when oil ducts become clogged and infected. Cystic acne affects deeper skin tissue than inflammation on the skin commonly seen in acne. Cystic acne is most common on the face and typically occurs in the teenage years.
Hidradenitis suppurativa: Hirradenitis suppurativa is a condition in which there are multiple abscesses that form under the arm pits and often in the groin area. These areas are a result of local inflammation of the sweat glands. This form of skin infection is difficult to treat with antibiotics alone and typically requires a surgical procedure to remove the involved sweat glands in order to stop the skin inflammation.
Pilonidal cyst: Pilonidal cyst is a unique kind of abscess that occurs at the bottom of the tailbone. Pilonidal cysts often begin as tiny areas of infection in the base of the hair follicle (the area of skin from which hair grows). With irritation from direct pressure, over time the inflamed area enlarges to become a firm, painful, tender nodule making it difficult and uncomfortable to sit. These frequently form after long trips that involve prolonged sitting. Pilonidal cysts are more common in men than in women.
Other abscesses: Other types of abscesses include amebic liver abscesses (collection of pus in the liver caused by the intestinal parasite Entamoeba histolytica), anorectal (anal or rectal) abscesses, Bartholin's (glands located on either side of the vagina) abscesses, brain abscesses, epidural (outer covering of the brain and spinal cord) abscesses, peritonsillar (beside the tonsils) abscesses, pyogenic (puss generating) liver abscesses, skin abscesses, spinal cord abscesses, subcutaneous (under the skin) abscesses, and tooth abscesses.

Related Terms

Acquired immunodeficiency syndrome, AIDS, anorectal, bacteria, bacterium, Bartholin's gland, boil, carbuncle, cystic acne, diabetes, endocarditis, Entamoeba histolytica, epidural, furuncle, furunculosis, groin, Hirradenitis suppurativa, HIV, human immunodeficiency virus, immune, inflammation, meningitis, methicillin-resistant, MRSA, neutrophils, nosocomial, parasite, peritonsillar, pilonidal cyst, pneumonia, pus, pustule, pyogenic, Staph., Staphylococcus aureus,steroids, subcutaneous, sweat gland, vagina.