doctor going over the causes of abscesses

Abscess Causes

An abscess is an inflamed area of skin filled with pus. Anyone can develop an abscess, although certain populations are more susceptible to them. Abscesses can be very uncomfortable, and although some may heal in only a few days after seeking medical assistance, others can take a few weeks to fully return to normal. As with any infection, the best form of treatment is to engage in preventative measures. Of course, these can only be taken if you understand what causes an abscess to form. 

How does an abscess form?

Bacteria, viruses, and parasites can all cause an abscess, although internal abscesses can also be a result of swallowing foreign objects. They are considered to be a skin and soft tissue infection (SSTI). Generally, an abscess starts from a small cut or injury -- even pimples and ingrown hairs can leave the door open for the beginnings of an abscess. The open wound allows germs and parasites to slip under the skin, causing an infection. When the body detects the pathogen, the immune system sends white blood cells to fight it off. 

What causes an abscess?

According to the United Kingdom’s National Health Service (NHS), all these extra cells in such a small area cause swelling and inflammation; the surrounding tissue begins to die off. This creates a depression in the skin, which fills up with pus. Pus is a clear, yellow, or greenish substance composed of the pathogen, the white blood cells trying to fight it, and the dead tissue this causes. Eventually, an abscess forms. If the bacteria (or other germ) isn’t killed off quickly, more white blood cells will be sent to join the fight, which creates more dead tissue and more pus, making the abscess continue to swell and grow. 

So why don’t the white blood cells take care of the bacteria? There are a number of reasons. For example, an immune system that isn’t in great working order or having certain medical conditions (from diabetes to hidradenitis suppurativa) can make you more susceptible to issues like this, because the white blood cells just don’t have the oomph they need. Additionally, some people carry a bacteria called Staphylococcus aureus. Staph bacteria are especially common instigators of abscesses because they emit Panton-Valentine leukocidin, “a toxin ...which kills white blood cells,” according to NHS, thus inhibiting them from doing their job. 

What about internal abscesses?

Internal abscesses are less a result of boils or accidentally stabbing yourself with a dirty knife -- although injuries can cause them -- as they are of bacteria (as well as viruses or even fungi and parasites) delving into the abdomen. Abdominal surgeries can create a sort of path for bacteria to thread their way inside; infection in your abdomen can spread to cause an internal abscess as well, such as when an appendix bursts. NHS states that an abscess can even form in the lungs following infections such as pneumonia. Internal abscesses form on organs or in the areas between them, and can be significantly more uncomfortable than external abscesses. If you suspect you have an abscess inside or outside of your body, talk to your doctor right away. 

Last Updated: January 16, 2017