Topic Overview

What is pilonidal disease?

Pilonidal (say "py-luh-NY-dul") disease is a chronic skin infection in the crease between the buttocks. People with this condition have one or more cysts in that area that tend to get inflamed and infected. A pilonidal cyst may look like a small dimple (called a "pit" or "sinus"). Hair may stick out from it.

See a picture of a pilonidal cyst.

What causes a pilonidal cyst?

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

• A hair follicle in the skin becomes irritated or stretched. (The follicle is the sac that the hair grows from.) 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 further 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?

Pilonidal disease often has no symptoms. If a cyst gets infected (called an abscess), you may have:

• Redness or swelling.
• Pus or blood draining from the abscess.
• Pain when you walk or sit.

How is pilonidal disease diagnosed?

A physical exam 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 it is treated?

Pilonidal disease does not need treatment if it is not causing symptoms.

If the cyst gets infected or is a problem:

• You may need antibiotics.
• Your doctor may need to open and drain the cyst. This procedure can be done in the doctor's office under local anesthesia. It takes at least a month to heal.
• You may need to have surgery to remove the cyst. This surgery is more complex than draining the cyst and is usually done at an outpatient surgical center or hospital under general anesthesia. It may take 10 days to 6 weeks or longer to heal.

Cysts can come back after treatment.

What can you do at home for a pilonidal cyst?

While you are being treated for an infected cyst:

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

For cysts that are not causing symptoms:

• Keep the area dry and clean.
• Wear cotton underwear and clothing.
• Try not to sit on hard surfaces for long periods of time.
• Keep the area free of hair. Talk with your doctor about the best method of hair removal for you. For example, you may:
  • Shave the area.
  • Use a hair-removing lotion (depilatory), as long as the area isn't irritated.
  • Have electrolysis or laser hair removal to keep hair away longer.

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