A pilonidal cyst is a fluid-filled developmental defect at the base of the spine.
The terms cyst, sinus, and abscess refer to different stages of the disease process.
While the cyst is not serious, it can become infected and should therefore be treated. When a pilonidal cyst gets infected, it forms an abscess, eventually draining pus through a sinus. The abscess causes pain, a foul smell, and drainage.
A pilonidal cyst 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.
The following factors increase your chance of developing a pilonidal cyst:
A pilonidal cyst may cause:
Your doctor will ask about your symptoms and medical history. A physical exam will be done. You will be referred to a surgeon for treatment. There are no diagnostic tests required.
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:
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.
The abscess is lanced, 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.
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.
There are recent reports that laser hair removal in the area may be an effective treatment for pilonidal cysts.
To help reduce your chance of a pilonidal abscess:
American Society of Colon and Rectal Surgeons
Family Doctor—American Academy of Family Physicians
The College of Family Physicians of Canada
Pilonidal cyst. American Academy of Family Physicians website. Available at: http://familydoctor.org/familydoctor/en/diseases-conditions/pilonidal-cyst.html. Updated April 2014. Accessed September 4, 2014.
Pilonidal cyst. Swedish Medical Center Seattle website. Available at: http://www.swedish.org/services/colon-and-rectal-clinic/services/pilonidal-cyst#axzz2d6pXFkit. Accessed September 4, 2014.
Pilonidal disease. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed. Updated February 18, 2014. Accessed September 4, 2014.
Pilonidal sinus and cysts. The Children's Hospital of Philadelphia website. Available at: http://www.chop.edu/service/surgery-general-thoracic-and-fetal/conditions-we-treat/pediatric-surgery-pilonidal-sinus-and-cysts.html. Updated November 2008. Accessed September 4, 2014.
Sadick NS, Yee-Levin J. Laser and light treatments for pilonidal cysts. Cutis. 2006;78:125-128.
Last reviewed August 2014 by Michael Woods, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.