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A skin abscess is a localized collection of pus that generally develops in response to infection or to the presence of other foreign materials under the skin. An abscess is typically painful, and it appears as a swollen area that is warm to the touch. The skin surrounding an abscess often appears pink or red.
Abscesses can develop in many parts of the body, but they usually involve the skin surface. Skin abscesses are also referred to as boils, especially when they affect the deeper, or subcutaneous, layers of the skin. Common sites affected by abscesses include the armpits (axillary area) and inner thigh (groin), called hidradenitis suppurativa, also known as acne inversa (AI). Other types of abscesses involve the rectal area (perirectal abscess), the external vaginal area (Bartholin's abscess), and along the tailbone (pilonidal abscess). Inflammation surrounding hair follicles or sweat glands can also lead to the formation of abscesses. Abscesses can affect any organ, including the brain, kidneys, liver (hepatic abscess), stomach or intra-abdominal area, lungs, breast, neck, face, cheeks, multiple teeth or an individual tooth (dental abscess), gums, throat, or tonsils (peritonsillar abscess). Abscesses can also occur anywhere on the body, such as the fingers and toes, eyes, shoulders, knees, or a foot/both feet.
An abscess is not the same thing as a cyst. Both are fluid-filled lumps, but an abscess is infected while a cyst is not. However, a cyst can become infected and turn into an abscess.
Unlike other infections, antibiotics alone will not typically cure a skin abscess. In general, abscesses must open and drain to improve. Although sometimes an abscess will open and drain spontaneously, it often needs to be lanced (incision and drainage) by a health care provider. Certain abscesses may require a surgical drainage procedure in an operating room.
Skin abscesses are typically caused by either an inflammatory reaction to an infectious process (bacteria or parasite) or, less commonly, to a foreign substance within the body (a needle or a splinter, for example). Abscesses may develop because of obstructed oil (sebaceous) or sweat glands, inflammation of hair follicles on the body or scalp, or from minor breaks and punctures of the skin. Abscesses may also develop after a surgical procedure.
The infectious organisms or foreign material cause an inflammatory response in the body, which triggers the body's immune system to form a cavity or capsule to contain the infection and prevent it from spreading to other parts of the body. The interior of the abscess liquefies, and pus develops (which contains dead cells, proteins, bacteria, and other debris). This area then begins to expand, creating increasing tension and inflammation of the overlying skin.
The most common bacterial organism responsible for the development of skin abscesses is Staphylococcus aureus, although various other organisms can also lead to abscess formation. With the emergence of methicillin-resistant Staphylococcus aureus (MRSA), health care providers must now consider this organism as the possible cause when a skin abscess is encountered.
A major risk factor for developing skin abscesses includes a weakened immune system (either from chronic diseases or from medications), because the body's ability to fight infection is decreased. The following conditions are risk factors for developing abscesses and for getting recurrent or multiple abscesses:
The symptoms of a skin abscess vary depending on the location of the abscess, but in general, individuals will experience the following:
A skin abscess will sometimes rupture and drain spontaneously at home without any further complications. A ruptured abscess can be a good thing because the pus is released and the body has a better chance to heal on its own. However, in some instances, further evaluation by a doctor is necessary to prevent the progression and complications associated with a continuing infection. Consult a doctor if any of the following scenarios occurs with an abscess:
Go to a hospital's emergency department if any of these conditions occur with an abscess:
A skin abscess may be treated by a primary care provider (PCP), such as a general practitioner, family medicine specialist, internist, or pediatrician. One may also be seen by an emergency medicine specialist in a hospital emergency department. If surgery is required, a general surgeon can treat an abscess. A dermatologist, who specializes in disorders of the skin, may also treat a skin abscess.
The doctor will take a medical history and ask for information about the following:
Often, a skin abscess will not heal on its own without further intervention by a health care provider. Initially, an abscess may feel firm and hardened (indurated), at which time incision and drainage may not be possible. However, once the abscess begins to "come to a head" and it becomes softer and fluid-filled, a minor surgery to lance it to evacuate the pus and relieve the pressure is the best course of action. A doctor will open and drain the abscess (incision and drainage) using the following technique:
A boil is a skin infection that starts in a hair follicle or oil gland. At first, the skin turns red in the area of the infection, and a tender lump develops. After four to seven days, the lump starts turning white as pus collects under the skin. If the infection spreads to the deeper tissues of the skin, then it becomes an abscess or furuncle.
