Pilonidal Sinus and Cysts

What are pilonidal sinus and cysts?

A pilonidal cyst and sinus can be one or several openings in the skin between the buttocks. Often there is a cyst at the base of the sinus, the passage that leads to an abscess, which is a collection of pus.

Most pilonidal sinuses become infected when loose hair and debris collect in them. These cysts most commonly form over the tailbone. Hair and sweat — as well as friction and pressure — may push hair into the skin when your child is sitting. The first sign of a pilonidal cyst may be an abscess. Symptoms include swelling, warmth, redness and tenderness at the site, but cysts may also be present without symptoms until adolescence or early adulthood.


If your child has had multiple infections or considerable pain, surgery is an effective way to relieve pilonidal cyst pain and prevent the spread of infection. During this operation, the surgeon will drain the abscesses, and, if necessary, remove the sinus tracts or tunnels and cysts. If your child has an infected cyst, the surgeon may leave the incision open to drain the infection after surgery.

Follow-up care

Your child may be admitted overnight for observation and pain management. She'll receive pain medicine, either by mouth or through an intravenous (IV) line. The medical team will check her wound and give her antibiotics through an IV.

Your child may go home as soon as her pain is under control with oral (by mouth) medications. Here's what to expect at home after your child's surgery:

  • Healing can be slow and may take several weeks after draining the abscess or after having surgery to remove the sinus. If the sinus is removed, keeping pressure off of the incision is imperative to good wound healing. Often children have the problem return in the same or a nearby area several months to a year after healing. No one knows the reason for this.
  • Before your child is discharged, the hospital staff will teach you how to change his dressing. Remember to change it every day. If your child needs dressings, a home care company may help you after your child goes home. These companies can provide you with any necessary supplies.
  • Your child may have a small rubber drain in the wound for about one week; it will be removed during her follow-up appointment with the surgeon. The drain may fall out while your child is at home, if that happens, please call the office and let the team know.
  • Your child may bathe or shower two days after surgery, even if she has a surgical drain in place.

When to call the doctor

Please call your child's surgeon's office (at Children's Hospital, call 215-590-2730) if:

  • Your child has any signs of infection around the incision, including redness, swelling or yellow or green drainage
  • Your child has a fever higher than 101.5 degrees F by mouth
  • Your child has pain that can't be controlled with the prescribed pain medications
  • You have any questions or concerns

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