Pilonidal Cyst

(Pilonidal Sinus; Pilonidal Abscess)

Pronounced: PIE-low-NIGH-dull sist
by Ricker Polsdorfer, MD

Definition

A pilonidal cyst is a fluid-filled defect. It is found at the base of the spine, or “tailbone” area.

The terms cyst, sinus, and abscess refer to different stages of the disease process.

  • Cyst—not infected
  • Abscess—pocket of pus
  • Sinus—opening between a cyst (or other internal structure) and the outside

When a pilonidal cyst is infected, it forms an abscess, eventually draining pus through a sinus. Pilonidal cysts are harmless until they get infected. At this point they form an abscess that causes pain, a foul smell, and drainage. This is more likely to occur in young Caucasian men with a lot of hair in the region.

This condition is not serious, but since it is an infection like a boil or carbuncle, it can enlarge and become uncomfortable. Therefore, it should be treated.

Pilonidal Cysts

Pilonidal cyst
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Causes

A pilonidal condition may be congenital or acquired. If congenital, it probably began as a defect that existed when you were born. Sometime later, the defect allowed an infection to develop. If acquired, it may be the enlargement of a simple hair follicle infection or the result of a hair penetrating the skin and causing an infection.

Risk Factors    TOP

The following factors increase your chance of developing a pilonidal abscess:

  • Personal or family history of similar problems (such as acne, boils, carbuncles, folliculitis, sebaceous cysts)
  • Large amounts of hair in the region
  • Tailbone injury
  • Horseback riding, cycling

Symptoms    TOP

If you experience these symptoms, they are due to a pilonidal abscess that needs to be treated by your doctor:

  • Painful swelling over your sacrum (just above your tailbone)
  • A foul smell or pus draining from that area

Diagnosis    TOP

Your doctor will ask about your symptoms and medical history, and perform a physical exam. You will be referred to a surgeon for treatment. There are no diagnostic tests required.

Treatment    TOP

Talk with your doctor about the best treatment plan for you. The choice of treatment will depend on the extent of the condition and your general overall health. Treatment options include:

Home Treatment

As with all localized infections under the skin, hot water soaks will draw out the infection. This will not completely cure the condition, but it will help.

Incision and Drainage

The abscess is sliced, the pus drained, and the wound is packed with sterile gauze. This helps it heal from the inside out. But this usually does not cure the problem because abnormal tissue remains.

Excision

To completely cure the condition, all affected tissue needs to be removed. This is a more extensive surgical procedure than simple incision and drainage. The surgical wound may be closed with sutures or left open to heal from the inside.

Laser Hair Removal

There are recent reports that laser hair removal in the area may be effective treatment for pilonidal cysts.

Prevention    TOP

Here are ways to reduce your chance of getting a pilonidal abscess:

  • Keep the area clean and dry.
  • Avoid sitting for a long time on hard surfaces.
  • Remove hair from the area.

RESOURCES:

American Academy of Dermatology
http://www.aad.org
The American Board of Dermatology, Inc.
http://www.abderm.org

CANADIAN RESOURCES:

BC Health Guide
http://www.bchealthguide.org
Canadian Dermatology Association
http://www.dermatology.ca

References:

Merck CMC Research. The Merck Manual. 17th ed. West Point, PA: Merck and Co; 1999.
Pilonidal disease. Palo Alto Medical Foundation website. Available at: http://www.pamf.or.... Updated January 13, 2006. Accessed June 15, 2008.
The pilonidal support alliance. Pilonidal Support Alliance website. Available at: http://www.pilonidal.org/. Updated May 24, 2008. Accessed June 15, 2008.
Sadick NS, Yee-Levin J. Laser and light treatments for pilonidal cysts. Cutis. 2006;78:125-128.
Last reviewed September 2012 by Peter Lucas, MD
Last Updated: 09/30/2012