Conditions Basics

What is pilonidal disease?

Pilonidal (say "py-luh-NY-dul") disease is a long-term skin infection. The infection develops in a cyst at the top of or next to the crease between the buttocks. The cyst may look like a small dimple, which is called a "pit" or "sinus." Hair may grow from the pit, and you may have several pits.

What causes it?

Experts think pilonidal cysts may form in one of three ways:

• A hair follicle in the skin becomes irritated or stretched. This may be caused by exercise that affects the buttocks area (such as horseback riding or cycling), tight clothing around the buttocks, heat, or heavy sweating. The hair follicle may become blocked and infected and then open into the surrounding tissue, forming an abscess. Continued exercise or walking often pulls hair into the abscess.
• A loose hair may get trapped in the crease between the buttocks. This is more common with coarse or stiff hair. The hair can poke into the skin, especially if there is already an irritated hair follicle. Walking and exercise can pull the hair farther into the skin. A cyst then forms around the hair and can become infected.
• Some cysts may be present at birth (congenital).

What are the symptoms?

• You may have no symptoms.
• If the cyst is infected, you may:
  • Have redness or swelling in the area.
  • Have cloudy fluid or blood draining from the cyst.
  • Find it hard to walk or sit because of pain.
  • Have a fever. This is not common.

How is it diagnosed?

A physical examination of the buttocks is usually all doctors need to diagnose pilonidal disease. You probably won't need any other tests unless the area doesn't heal or your doctor thinks there may be another problem.

How is a pilonidal cyst treated?

If the cyst gets infected or is a problem, your doctor may need to open and drain the cyst. This procedure can be done in your doctor's office. You may get antibiotics if the infection is severe. The cyst may take a month or more to heal.

You may need to have surgery (excision) to remove the cyst. Surgery may need to be done if:

• It gets infected again.
• It doesn't heal after being drained.
• Your cyst has more than one opening.

Surgery may be done at an outpatient surgical centre or hospital. It may take 6 weeks or longer to heal.

Cysts can come back after being drained. Surgery works better as a permanent cure.

How can you care for yourself?

While you are being treated for an infected cyst:

• Keep the area dry and clean. Your doctor may want you to use soap or an alcohol swab to clean the area.
• Soak in a warm tub several times a day.
• Take non-prescription pain medicine if needed.

For cysts that are not causing symptoms or after you have had surgery to remove a cyst:

• Keep the area dry and clean.
• Try not to sit on hard surfaces for long periods of time.

Keeping the area free of hair may also help. Talk with your doctor about what he or she recommends.