What is pilonidal disease and what causes it?
Pilonidal disease is a chronic infection of the skin in
the region of the buttock crease (Figure 1). The
condition results
from a reaction to hairs embedded in the skin, commonly
occurring in the cleft between the buttocks. The disease
is more common in men than women and frequently occurs between
puberty and age 40. It is also common in obese people and
those with thick, stiff body hair.
Figure 1: Pilonidal disease is a chronic skin infection
in the buttock crease area. Two small openings are shown
(A).
What are the symptoms?
Symptoms vary from a small dimple to a large painful mass.
Often the area will drain fluid that may be clear, cloudy
or bloody. With infection, the area becomes red, tender,
and the drainage (pus) will have a foul odor. The infection
may also cause fever, malaise, or nausea.
There are several common patterns of this disease. Nearly
all patients have an episode of an acute abscess (the area
is swollen, tender, and may drain pus). After the abscess
resolves, either by itself or with medical assistance, many
patients develop a pilonidal sinus. The sinus is a cavity
below the skin surface that connects to the surface with
one or more small openings or tracts. Although a few of
these sinus tracts may resolve without therapy, most patients
need a small operation to eliminate them.
A small number of patients develop recurrent infections
and inflammation of these sinus tracts. The chronic disease
causes episodes of swelling, pain, and drainage. Surgery
is almost always required to resolve this condition.
How is pilonidal disease treated?
The treatment depends on the disease pattern. An acute abscess
is managed with an incision and drained to release the pus,
and reduce the inflammation and pain. This procedure usually
can be performed in the office with local anesthesia. A
chronic sinus usually will need to be excised or surgically
opened.
Complex or recurrent disease must be treated surgically.
Procedures vary from unroofing the sinuses to excision (Figure
2) and possible closure with flaps. Larger operations
require longer healing times. If the wound is left open,
it will require dressing or packing to keep it clean. Although
it may take several weeks to heal, the success rate with
open wounds is higher. Closure with flaps is a bigger
operation that has a higher chance of infection; however,
it may be required in some patients. Your surgeon will discuss
these options with you and help you select the appropriate
operation.
Figure 2: Drawing B is a side view showing how
most of the inflammation is deep under the skin just outside
the coccyx (tailbone). The dashed line shows how it may
be opened or unroofed. Dashed line in drawing C shows excision
of all inflamed tissue.
What care is required after surgery?
If the wound can be closed, it will need to be kept clean
and dry until the skin is completely healed. If the wound
must be left open, dressings or packing will be needed to
help remove secretions and to allow the wound to heal from
the bottom up.
After healing, the skin in the buttocks crease must be
kept clean and free of hair. This is accomplished by shaving
or using a hair removal agent every two or three weeks until
age 30. After age 30, the hair shaft thins, becomes softer
and the buttock cleft becomes less deep.
