A pilonidal cyst is a swelling that starts under the skin on the sacrum near the tailbone. It may look like a small dimple. It can fill with skin oils, hair, and dead skin cells. It may stay small or grow larger. Because it often has an opening to the surface, it may become infected with normal skin bacteria.
The cause of pilonidal cysts has been debated since they were first recognized. It may be present at birth and go unnoticed. Injury, rubbing, or skin irritation may also cause pilonidal cysts. It can also be caused by an ingrown hair. Most likely, the cause is a combination of these things. Because some injury or irritation can lead to pilonidal cysts, it can be more common in people who sit or drive a lot for work.
A pilonidal cyst may be small and painless. If it's inflamed or infected, you may have these symptoms:
Irritation or redness
The cyst can swell and drain on its own. The swelling and drainage can come and go.
Your pilonidal cyst was drained with a small incision using local anesthesia.
After the incision and drainage, gauze packing may be inserted into the opening. If so, it should be removed in 1 to 2 days. Antibiotics are not required in the treatment of a simple abscess, unless the infection is spreading into the skin around the wound. The wound will take about 1 to 2 weeks to heal depending on the size of the cyst.
Pus may drain from the wound for the first few days. Cover the wound with a clean dry bandage. Change the bandage if it becomes soaked with blood or pus, or if it gets soiled with feces or urine.
If gauze packing was placed inside the cyst cavity, you may be told to remove it yourself. You may do this in the shower. Once the packing is removed, you should wash the area carefully in the shower once a day. Do this until the skin opening has closed. It's OK to direct the shower spray directly into the opening if this is not too painful.
Take acetaminophen or ibuprofen for pain, unless you were given a different pain medicine to use. Talk with your healthcare provider before using these medicines if you have chronic liver or kidney disease or have ever had a stomach ulcer or digestive bleeding. Also talk with your provider if you are taking blood-thinner medicines.
If you were given antibiotics, take them until they are gone. It's important to finish the antibiotics even if the wound looks better. This is to make sure the infection has cleared completely.
Use antibiotic cream or ointment if your healthcare provider tells you to do so.
Once this infection has healed, the following may decrease the risk of future infections:
Keep the area of the cyst clean by bathing or showering daily.
Don't wear tight-fitting clothing to minimize perspiration and irritation of the skin.
Pilonidal cysts that come back may be completely removed by surgery. But this can only be done at a time when there is no infection. Ask your healthcare provider for more information.
Follow up with your healthcare provider, or as advised. If a gauze packing was inserted in your wound, it should be removed in 1 to 2 days, or as directed. Check your wound every day for the signs of infection listed below.
When to seek medical advice
Call your healthcare provider right away if any of these occur:
Pus continues to come from the cyst for 5 days after the incision
Increasing redness, local pain, or swelling
Fever of 100.4°F (38.0°C) or higher for more than 2 days, or as advised by your healthcare provider