An abscess is a collection of pus within the body, in the tissues, organs or internal cavities, caused by the body’s response to an infection. An skin abscess is a furuncle and carbuncle, also known as blisters, boils or blains, and these pus swellings usually occur on the skin (cutaneous) or just underneath the skin (subcutaneous) where it may protrude through the skin. A deep seated abscess is a ‘ball of pus’ that grows internally and is usually not visible from the outside.
How does an abscess develop?
Pathogenesis of an abscess
Most commonly, an abscess forms as a result of a bacterial infection although a fungal or protozoal infection can also trigger an abscess formation. When an infection occurs, the body ‘walls’ it off and floods it with immune cells. Pus is a collection of these white blood cells (immune cells), dead body cells and remnants, as well as the bacteria. The abscess is the site of an ongoing battle between the body and the invading bacteria or fungi. Although the invading microorganism is contained within the abscess, if untreated, the infection can spread further or the abscess can enlarge significantly thereby impacting on vital organs.
The body’s immune system usually protects the body from infections but in a patient that is immunocompromised like in HIV/AIDS, or if there are certain chronic conditions, the invading microorganism may be able to establish itself within the body.
What causes an abscess?
Causes of an Abscess
The cause of an abscess is a microorganism, like a bacteria or fungus, and the abscess forms to wall off the infection. The internal environment of the body is sterile, meaning that there are no microogranisms, except those living in the gastrointestinal tract. However, bacteria and fungi can enter the body tissues, organs or usually sterile cavities through one of the following means.
This may occur through the penetration of unsterile objects into the tissue, like ‘dirty needles’ or through a stab wound.
Spread from an Adjacent Site
If there is an infection in a neighboring organ, the bacteria or fungus can spread to other organs or tissue in the area. The spread can also occur from cavities which naturally contain bacteria, like the mouth, nose or gastrointestinal tract.
Dissemination through Lymph and Blood
The lymphatic fluid and blood supply travels to every site through a network of vessels and bacteria or fungi from the site of one infection can enter the blood and spread to another site. This may also cause blood poisoning or sepsis, which if untreated, can be fatal.
How will I know if I have an abscess?
Signs and Symptoms of an Abscess
In a superficial abscess (cutaneous or subcutaneous), pain and tenderness will usually alert you to the presence of an abscess. Other signs and symptoms of a superficial abscess include swelling and redness at the affected area. Fever may be present if the infection and inflammation has spread to surrounding skin and connective tissue (cellulitis).
A deep seated abscess may not be as easy to identify and further diagnostic investigation like an xray or MRI scan may be necessary. Signs and symptoms of an internal abscess may include :
- Pain and tenderness in the region of the abscess
- Weight loss due to the infection
- Loss of appetite
Other signs and symptoms may also be present depending on thee organ that is affected.
What will happen if an abscess is not treated?
Complications of an Abscess
Apart from growing in size and damaging the infected tissue or organ, the infection will also spread to other areas in the body through the lymphatic fluid or blood resulting in a generalized infection (septicemia). This is fatal if emergency medical treatment is not instituted immediately.
How is an abscess treated?
Treatment of an Abscess
Draining the abscess as soon as possible is important. This may be done with an incision and drainage for a superficial abscess or fine needle aspiration for deeper lying abscesses. In certain areas of the body which cannot be reached easily, like in a brain abscess, surgery may be necessary. Drugs like antibiotics are usually necessary because most abscesses are caused by bacteria but systemic antifungals may be required for an abscess due to a fungus. In severe cases where the infection has progressed, an IV (intravenous) drip has to be set up for antibiotic administration as well as fluid and electrolytes to treat dehydration.