While the cyst is not serious, it can become infected and may need to be treated if problems develop. When a pilonidal cyst gets infected, it forms an abscess, eventually draining pus through a sinus.

Pilonidal Cysts

Causes

A pilonidal cyst may be congenital or acquired. If congenital, it probably began as a defect that existed at birth. 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

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

Personal or family history of pilonidal disease
Large amounts of hair in the region
Midline skin pits or deep gluteal cleft
Tailbone irritation or injury
Continuous bouncing in seated position, such as horseback riding or cycling
Prolonged sitting
Obesity

Symptoms

A pilonidal cyst may cause:

Painful swelling over your sacrum, which is the area just above your tailbone
A foul smell or pus draining from that area

Diagnosis

You will be asked about your symptoms and medical history. A physical exam will be done. You may be referred to a surgeon for treatment. There are no diagnostic tests required.

Treatment

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, warm water soaks will draw out the infection. This will not completely cure the condition, but it will help.

Incision and Drainage

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

Excision

To completely cure the condition, all affected tissue needs to be removed. It may be considered if you have repeated infections. 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.

Prevention

To help reduce your chances of a pilonidal abscess:

Keep the area clean and dry
Avoid sitting for a long time on hard surfaces
Remove hair from the area
Talk to your doctor about laser hair removal

RESOURCES:

American Society of Colon and Rectal Surgeons
https://www.fascrs.org

Family Doctor—American Academy of Family Physicians
https://familydoctor.org

CANADIAN RESOURCES:

HealthLink BC
https://www.healthlinkbc.ca

The College of Family Physicians of Canada
http://www.cfpc.ca

References:

Pilonidal cyst. Family Doctor—American Academy of Family Physicians website. Available at: https://familydoctor.org/condition/pilonidal-cyst. Updated April 2014. Accessed August 18, 2017.

Pilonidal cyst. Swedish Medical Center Seattle website. Available at:
...(Click grey area to select URL)
Accessed August 18, 2017.

Pilonidal disease. EBSCO DynaMed Plus website. Available at: http://www.dynamed.com/topics/dmp~AN~T114205/Pilonidal-disease . Updated January 30, 2017. Accessed August 18, 2017.

Pilonidal sinus and cysts. Children's Hospital of Philadelphia website. Available at:
...(Click grey area to select URL)
Accessed August 18, 2017.

Sadick NS, Yee-Levin J. Laser and light treatments for pilonidal cysts. Cutis. 2006;78(2):125-128.

Last reviewed September 2018 by EBSCO Medical Review Board Michael Woods, MD, FAAP
Last Updated: 8/18/2017

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