FAMILY MEDICINE® COLUMN

By John C. Wolf, D.O.Associate Professor of Family Medicine Ohio University College of Osteopathic Medicine

DRAINING PILONIDAL CYST GOOD TREATMENT, BUT SURGERY CAN CURE

Question: I’ve recently been diagnosed with a pilonidal abscess. My doctor used a sharp knife to cut open my behind and drain the abscess and said I’d be better in a few days. He was correct. The pain and swelling are gone now, but I’d like to know what caused it in the first place?

Answer: A pilonidal abscess is a skin infection in the “natal cleft” between the buttocks. Some people have a sinus-like structure in this cleft -- called a pilonidal cyst -- that is prone to infection. In mild cases it produces discomfort and redness. Typically, though, for those individuals whose discomfort is bad enough to get them to the doctor’s office, their pilonidal sinus has become swollen and inflamed as well as quite painful.

A pilonidal cyst contains hair that has grown down into the skin instead of up as it normally does. While it technically doesn’t become an abscess until bacteria invade and cause an infection, many doctors use the terms pilonidal cyst and pilonidal abscess interchangeably. Pilonidal cysts are more common in those who have an abundance of body hair or who have considerable rubbing of the skin in the fold of the buttocks. That is why overweight, hairy men account for 85 percent of the cases. A pilonidal cyst doesn’t always progress into a pilonidal abscess, but it certainly isn’t a rare complication of the condition.

A pilonidal abscess is an infection that the body has been unable to quickly subdue. The body sends many white blood cells to the infected area to destroy invading bacteria. This microscopic war goes on to create the red-colored, swollen area that is characteristic of an infection. If the war is prolonged, an accumulation of infectious debris forms. This collection of worn out white blood cells, bacteria, body fluids and blood stretches and fills the tissue inside the pilonidal cyst, forming an abscess.
Since antibiotics kill bacteria, it would seem that they should be the proper treatment for an abscess. This would be true early in the infection. However, once the infection progresses to form an abscess, antibiotics can no longer be delivered to the abscessed area through the blood stream in high enough concentrations to destroy bacteria. Opening the abscess to drain the pus, the procedure you elegantly described in your question, is the necessary treatment. Antibiotics may be prescribed after the abscess has been drained, but this is not always necessary.

Once an abscess has been drained and the infection controlled, the condition returns to that of a pilonidal cyst. That means that it is possible to have another abscess develop. The best way to avoid subsequent abscesses is to have the skin containing the cyst removed. The surgical wound will quickly heal, leaving healthy skin.

"Family Medicine" is a weekly column.

To submit questions, write to: John C. Wolf, D.O., Ohio University College of Osteopathic Medicine, Grosvenor Hall, Athens, Ohio 45701.

Past columns are available online at http://www.FamilyMedicineNews.org.