Overview - What Is a Pilonidal Cyst?

pilonidal cyst is a pocket of hair, skin and oils, that can be above your buttocks or on either side of the buttock cleft. A pilonidal cyst looks like a large pimple or bump.

Sometimes, a pilonidal cyst can get infected. When this happens, it may fill with pus (a thick white, yellow or green liquid made of dead skin cells and germs, like bacteria). This may be painful.

Causes

A pilonidal cyst is usually caused by ingrown hairs that may be inflamed or become infected (irritated and swollen).

Anyone can get a pilonidal cyst, but they may be associated with:

  • Thick or rough body hair
  • Being overweight
  • Sitting for long periods of time
  • Sweating more than usual
  • Family history of pilonidal cysts
  • Smoking
  • Wearing tight clothing

Symptoms

Symptoms of a pilonidal cyst may include:

  • Sometimes simple swelling just above your buttocks
  • Pain and swelling (if the cyst becomes inflamed or infected)
  • Hair coming out of the cyst
  • Pus or blood draining from an opening in the skin
  • Bad smell from the cyst
  • Tenderness around the cyst
  • Fever (not often)

Treatment

There are different treatments for an inflamed or infected pilonidal cyst. Treatment depends on whether the cyst drains on its own or not. The doctor will talk with you about which treatment is best for you.

Treatments can include:

  • Antibiotics. In some cases, antibiotics may be the best first choice. The infection may get better without the need for lancing (draining) or surgery.
  • Lancing (draining) the cyst. This is more common if the cyst is tender, has gotten larger and has softened where there may be pus under the skin. The doctor will numb your skin and make a small hole to let the cyst drain. The doctor may wash out the wound and pack it with gauze, leaving a small piece of gauze outside. This helps the cyst heal.
  • Surgery to remove the cyst may be needed if swelling and infections keep coming back. The doctor will talk with you about the different surgeries, depending on your medical history and physical exam. In some surgeries, the cyst is drained, removed and closed with stitches. In other surgeries, the cyst is drained and removed, but the doctor leaves the wound open. This helps the wound heal slowly and makes it less likely for the cyst to come back.

Outcomes

While some cysts may require a single treatment, the total treatment for some cysts will need more than one visit to the doctor or more than one procedure to heal completely.

An infection in a pilonidal cyst is more likely to be treated successfully if you take antibiotics as prescribed and, if necessary, have the cyst lanced (drained). If you need more complex surgery to remove the cyst, healing will take longer. Your doctor will tell you how and when you can return to school, sports, gym class or certain types of exercise.

If the cyst comes back, the doctor will talk with you about additional treatment.