Pilonidal Cyst

Pilonidal cyst is a fluid-filled sac that forms beneath the skin near the tailbone, at the top of the crease of the buttocks (pilonidal area). If the cyst is not large and not infected, it may not cause any problems.

If the cyst becomes irritated or infected, it may get larger and fill with pus. An infected cyst is called an abscess. A pilonidal abscess may cause pain and swelling, and it may need to be drained or removed.

What are the causes?

The cause of this condition is not always known. In some cases, a hair that grows into your skin (ingrown hair) may be the cause.

What increases the risk?

You are more likely to get a pilonidal cyst if you:

• Are male.
• Have lots of hair near the crease of the buttocks.
• Are overweight.
• Have a dimple near the crease of the buttocks.
• Wear tight clothing.
• Do not bathe or shower often.
• Sit for long periods of time.

What are the signs or symptoms?

Signs and symptoms of a pilonidal cyst may include pain, swelling, redness, and warmth in the pilonidal area. Depending on how big the cyst is, you may be able to feel a lump near your tailbone. If your cyst becomes infected, symptoms may include:

• Pus or fluid drainage.
• Fever.
• Pain, swelling, and redness getting worse.
• The lump getting bigger.

How is this diagnosed?

This condition may be diagnosed based on:

• Your symptoms and medical history.
• A physical exam.
• A blood test to check for infection.
• Testing a pus sample, if applicable.

How is this treated?

If your cyst does not cause symptoms, you may not need any treatment. If your cyst bothers you or is infected, you may need a procedure to drain or remove the cyst. Depending on the size, location, and severity of your cyst, your health care provider may:

• Make an incision in the cyst and drain it (incision and drainage).
• Open and drain the cyst, and then stitch the wound so that it stays open while it heals (marsupialization). You will be given instructions about how to care for your open wound while it heals.
• Remove all or part of the cyst, and then close the wound (cyst removal).

You may need to take antibiotic medicines before your procedure.

Follow these instructions at home:

Medicines

• Take over-the-counter and prescription medicines only as told by your health care provider.
• If you were prescribed an antibiotic medicine, take it as told by your health care provider. Do not stop taking the antibiotic even if you start to feel better.

General instructions

• Keep the area around your pilonidal cyst clean and dry.
• If there is fluid or pus draining from your cyst:
  • Cover the area with a clean bandage (dressing) as needed.
  • Wash the area gently with soap and water. Pat the area dry with a clean towel. Do not rub the area because that may cause bleeding.
• Remove hair from the area around the cyst only if your health care provider tells you to do this.
• Do not wear tight pants or sit in one position for long periods at a time.
• Keep all follow-up visits as told by your health care provider. This is important.

Contact a health care provider if you have:

• New redness, swelling, or pain.
• A fever.
• Severe pain.

Summary

• A pilonidal cyst is a fluid-filled sac that forms beneath the skin near the tailbone, at the top of the crease of the buttocks (pilonidal area).
• If the cyst becomes irritated or infected, it may get larger and fill with pus. An infected cyst is called an abscess.
• The cause of this condition is not always known. In some cases, a hair that grows into your skin (ingrown hair) may be the cause.
• If your cyst does not cause symptoms, you may not need any treatment. If your cyst bothers you or is infected, you may need a procedure to drain or remove the cyst.