A gathering of pus caused by infection by microorganisms, often bacteria. Pus is formed from destroyed cell tissues, leukocytes (a type of white blood cell) that have been carried to the area to fight infection, and dead and live microorganisms. A lining (called a pyogenic membrane) often forms around the abscess.
Abscess can develop in any organ, and in soft tissues of the skin, sometimes as a collar-stud abscess, a small cavity that connects to a larger cavity in deeper tissues. Common sites of abscess include groin, breast, gums and armpit. Rarer sites include the brain and liver.
Cause and Incidence
Common bacteria are the usual cause of abscesses, although fungal infections are another cause. Amoebae (single-celled microorganisms) are important cause of liver abscesses (see amoebiasis). Infectious organisms reach internal organs via the bloodstream or penetrate to tissues under skin through a contaminated bite or wound. People with weakened immune systems such as those taking immune suppressant drugs and those with AIDS or HIV infection are especially susceptible to abscess.
Abscesses can cause pain, depending on where it occurs. Abscesses may produce a sensation of intense pressure and those close to the skin can cause redness and swelling. Most bigger abscesses cause fever sometimes with chills, malaise and sweating.
Antibiotic drugs are typically prescribed to treat bacterial infections, antifungal drugs are used to treat fungal infections, and amoebicides are used for amoebiasis. Generally abscesses need to be drained by making a cut in the lining of the abscess cavity to allow the pus to escape; a tube can be left in place to allow continuous drainage. Some abscess burst and drain of their own accord.
Often abscess subside following just drainage; others subside after a combination of drug treatment and drainage. Sometimes the presence of an abscess within a vital organ damages enough surrounding tissue to cause permanent loss of normal function or even death.