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Pilonidal Cyst

  • Ricker Polsdorfer, MD
Publication Type:


Pilonidal Cyst

(Pilonidal Sinus; Pilonidal Abscess)


A pilonidal cyst is a fluid-filled pocket in the skin near the tailbone.

The cyst is not serious but can become infected. It should therefore be treated.

When a pilonidal cyst gets infected, it forms an abscess. The abscess eventually drains pus through a sinus. A sinus is an opening between a cyst or other internal structure and the outside.

Pilonidal Cysts.

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A pilonidal cyst may be caused by:

  • A defect from birth that allows an infection to develop
  • A hair follicle infection
  • Ingrown hairs
  • Injury, rubbing, or skin irritation to the area

Risk Factors

Pilonidal cysts are more common in males and young adults. Other things that raise the risk are:

  • A personal or family history of pilonidal disease
  • Large amounts of hair in the area
  • Midline skin pits or a deep buttocks crack
  • Continuous bouncing when seated, such as horseback riding or cycling
  • Sitting for long periods of time
  • Obesity


A pilonidal cyst may cause:

  • Painful swelling in the area just above the tailbone
  • A foul smell or pus draining from that area


The doctor will ask about symptoms and past health. A physical exam will be done. This is enough to diagnose a pilonidal cyst.


Treatment will depend on:

  • How severe the condition is—if there is an abscess or sinus
  • If the person has had the condition before
  • How fast the person recovers

Options that may help include:

  • Warm water soaks—to ease symptoms
  • Cutting and draining the cyst—done in the doctor's office
  • Antibiotics by IV or applied to the skin—do not heal cysts on their own

Other treatments may include:

  • Laser therapy—to remove hair that could cause cysts to grow back
  • Phenol injections—to treat and prevent mild and moderate cysts

Surgery is an option if:

  • The cyst has gotten worse and formed a sinus
  • Cysts are chronic—keep coming back

With surgery all affected tissue needs to be removed. The surgeon might close the wound with sutures or leave it open to heal from the inside.


To help reduce the risk of a pilonidal abscess:

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




  • Johnson EK, Vogel JD, et al. The American Society of Colon and Rectal Surgeons' Clinical Practice Guidelines for the Management of Pilonidal Disease. Dis Colon Rectum. 2019;62(2):146-157.
  • Pilonidal cyst. Cleveland Clinic website. Available at:https://my.clevelandclinic.org/health/diseases/15400-pilonidal-disease.
  • Pilonidal cyst. Family Doctor—American Academy of Family Physicians website. Available at: https://familydoctor.org/condition/pilonidal-cyst.
  • Pilonidal disease. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/pilonidal-disease.
  • Pilonidal sinus and cysts. Children's Hospital of Philadelphia website. Available at: http://www.chop.edu/conditions-diseases/pilonidal-sinus-and-cysts.


  • Mark Arredondo, MD
Last Updated:

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.