What is Pilonidal Disease?

What is Pilonidal Disease?

A nest of hairs

Pilonidal disease is not a cyst (an epithelial-lined sac), it is an abscess (a cavity filled with infected fluid and/or debris).  The fluid, if present, is infected fluid called purulent material or pus, and the debris is usually loose hair.  In fact pilonidal means “nest of hairs.”  Around half of all pilonidal abscesses contain hairs.  The hairs have been shed from other parts of the body (such as the scalp, back etc.) and then become lodged in an unusually deep cleft near the tailbone. They are not ingrown hairs. This is why shaving the affected area is usually of little help.

Symptoms of pilonidal disease

Pilonidal disease can cause a variety of symptoms which may happen all the time, may come and go, may be mild, or may be severe.  These symptoms include:

  • Pain/discomfort or swelling above the anus or near the tailbone that comes and goes
  • Opaque yellow (purulent) or bloody discharge from the tailbone area
  • Unexpected moisture in the tailbone region
  • Discomfort with sitting on the tailbone, doing sit-ups or riding a bike (any activities that roll over the tailbone area)

Be aware that most physicians are not trained to differentiate pilonidal disease from a perianal abscess or buttock abscess.  If you suspect that you have pilonidal disease, it is important to consult a Colon and Rectal Surgeon for a proper exam.

Why there?

Pilonidal disease affects a very specific area of the body called the natal cleft.  The natal cleft is the 2-3 inch valley under the tailbone that is hidden by one’s buttock cheeks when standing.  It is bracketed above by the coccyx (tailbone), and below by the anus.



Formation of abscesses

The abscess is believed to start when skin in the natal cleft stretches during sitting, breaking hair follicles and opening a pore or ‘pit’.  As one stands up, the movement causes a suction that pulls loose hair and debris into the now open ‘pore/pit’. Once lodged, the hairs can cause irritation if not expelled by the body or removed in time.  Chronic infection can develop in this hidden area and lead to the formation of tunnels (sinuses) from under the skin to areas outside the natal cleft.  Additional ‘pits’ can then develop leading to persistent or recurrent symptoms of pain, swelling, drainage, and even odor.  Many people with pilonidal disease have or develop ‘divots’ in their natal clefts, which further encourage the deposition of debris and the formation of more ‘pits’.

The deep clefts of people with pilonidal disease

Pilonidal disease typically develops in people with very deep natal clefts that have poor air circulation as a result of the deep cleft.  The only way to see pilonidal disease in these individuals is to part the buttock cheeks enough to visualize the pores or sinuses within the valley of the natal cleft.

Age and pilonidal disease

Pilonidal disease is common among young people.  The disease most often affects teens and young adults.  For unclear reasons, many, but not all, affected people will stop having symptoms of untreated disease by their 40s.

When pilonidal disease affects normal life

Pilonidal disease or failed surgical procedures aimed at treating the disease can lead to many months or years of discomfort, disability, and suffering.  Due to severe symptoms of pain or discharge, affected individuals may have trouble sitting for long periods of time, miss school or work, refrain from sports, or avoid close contact with friends.  Embarrassment from the condition may prevent individuals from using common locker rooms or wearing a bathing suit.  Unsuccessful surgical procedures may force individuals to remain at home and pack wounds in areas they can’t see or easily reach.

Pilonidal Surgery

This website should help you with this important decision: what is the best surgical option for...

1) primary disease with multiple,
2) primary disease with large pits,
3) persistent or recurrent disease,
4) an unhealed wound after one or several pilonidal surgeries

To schedule an appointment please call or email Jan at 415-668-0416 jdeboer@sfsurgery.com

Dr. Jeffrey Sternberg

Dr Jeffrey Sternberg is a leading Colon and Rectal surgeon.Dr. Sternberg is active in the national leadership of the American Society of Colon and Rectal Surgeons and has been elected President of the Northern California Chapter of the American Society of Colon and Rectal Surgery. Extending his commitment to the care of patients with Inflammatory Bowel Disease, Dr. Sternberg serves on the Board of Directors of the Northern California Chapter of the Crohn’s & Colitis Foundation of America.

Surgical Director, Center For Inflammatory Diseases
California Pacific Medical Center

Clinical Assistant Professor of Surgery
University of California San Francisco

Contact Dr. Sternberg through
San Francisco Surgical Medical Group.
415-668-0411
415-923-3020

Chrohns & Colitis Foundation

American Society of Colon and Rectal Surgeons