Epidermal Cyst

An epidermal cyst is sometimes called a sebaceous cyst, epidermal inclusion cyst, or infundibular cyst. These cysts usually contain a substance that looks "pasty" or "cheesy" and may have a bad smell. This substance is a protein called keratin. Epidermal cysts are usually found on the face, neck, or trunk. They may also occur in the vaginal area or other parts of the genitalia of both men and women. Epidermal cysts are usually small, painless, slow-growing bumps or lumps that move freely under the skin. It is important not to try to pop them. This may cause an infection and lead to tenderness and swelling.


Epidermal cysts may be caused by a deep penetrating injury to the skin or a plugged hair follicle, often associated with acne.


Epidermal cysts can become inflamed and cause:

  • Redness.

  • Tenderness.

  • Increased temperature of the skin over the bumps or lumps.

  • Grayish-white, bad smelling material that drains from the bump or lump.


Epidermal cysts are easily diagnosed by your caregiver during an exam. Rarely, a tissue sample (biopsy) may be taken to rule out other conditions that may resemble epidermal cysts.


  • Epidermal cysts often get better and disappear on their own. They are rarely ever cancerous.

  • If a cyst becomes infected, it may become inflamed and tender. This may require opening and draining the cyst. Treatment with antibiotics may be necessary. When the infection is gone, the cyst may be removed with minor surgery.

  • Small, inflamed cysts can often be treated with antibiotics or by injecting steroid medicines.

  • Sometimes, epidermal cysts become large and bothersome. If this happens, surgical removal in your caregiver's office may be necessary.


  • Only take over-the-counter or prescription medicines as directed by your caregiver.

  • Take your antibiotics as directed. Finish them even if you start to feel better.


  • Your cyst becomes tender, red, or swollen.

  • Your condition is not improving or is getting worse.

  • You have any other questions or concerns.


  • Understand these instructions.

  • Will watch your condition.

  • Will get help right away if you are not doing well or get worse.