A pilonidal cyst is a fluid-filled sac. It forms beneath the skin near your tailbone, at the top of the crease of your buttocks. A pilonidal cyst that is not large or infected may not cause symptoms or problems.

If the cyst becomes irritated or infected, it may fill with pus. This causes pain and swelling (pilonidal abscess). An infected cyst may need to be treated with medicine, drained, or removed.

 

 

 

What are the causes?

The cause of a pilonidal cyst is not known. One cause may be a hair that grows into your skin (ingrown hair).

What increases the risk?

Pilonidal cysts are more common in boys and men. Risk factors include:

• Having lots of hair near the crease of the buttocks.
• Being overweight.
• Having a pilonidal dimple.
• Wearing tight clothing.
• Not bathing or showering frequently.
• Sitting for long periods of time.

What are the signs or symptoms?

Signs and symptoms of a pilonidal cyst may include:

• Redness.
• Pain and tenderness.
• Warmth.
• Swelling.
• Pus.
• Fever.

How is this diagnosed?

Your health care provider may diagnose a pilonidal cyst based on your symptoms and a physical exam. The health care provider may do a blood test to check for infection. If your cyst is draining pus, your health care provider may take a sample of the drainage to be tested at a laboratory.

How is this treated?

Surgery is the usual treatment for an infected pilonidal cyst. You may also have to take medicines before surgery. The type of surgery you have depends on the size and severity of the infected cyst. The different kinds of surgery include:

• Incision and drainage. This is a procedure to open and drain the cyst.
• Marsupialization. In this procedure, a large cyst or abscess may be opened and kept open by stitching the edges of the skin to the cyst walls.
• Cyst removal. This procedure involves opening the skin and removing all or part of the cyst.

Follow these instructions at home:

• Follow all of your surgeon’s instructions carefully if you had surgery.
• Take medicines only as directed by your health care provider.
• If you were prescribed an antibiotic medicine, finish it all even if you start to feel better.
• Keep the area around your pilonidal cyst clean and dry.
• Clean the area as directed by your health care provider. Pat the area dry with a clean towel. Do not rub it as this may cause bleeding.
• Remove hair from the area around the cyst as directed by your health care provider.
• Do not wear tight clothing or sit in one place for long periods of time.
• There are many different ways to close and cover an incision, including stitches, skin glue, and adhesive strips. Follow your health care provider's instructions on:
• Incision care.
• Bandage (dressing) changes and removal.
• Incision closure removal.

Contact a health care provider if:

• You have drainage, redness, swelling, or pain at the site of the cyst.
• You have a fever.