The term refers to either an "epidermoid cyst," which
originates from the skin, or a "pilar cyst," which comes from hair follicles.
These cysts are closed sacs that can be found under the skin
of the entire body, except for the palms of the hands and soles of the feet. A
cyst usually is a slow-growing lump that can move easily under the skin. A foul
odor may be noticed from the overlying skin.
Sebaceous cysts form out of your sebaceous gland. The sebaceous gland produces
the oil called sebum that coats your hair and skin. Cysts can develop if the
gland or its duct, the passage where oil is able to leave, becomes damaged or
blocked. This usually occurs due to a trauma to the area. The trauma may be a
scratch, a surgical wound, or a skin condition, such as acne. Sebaceous cysts
grow slowly, so the trauma may have occurred months or weeks before you notice
Other causes of a
sebaceous cyst may include:
- a misshapen or deformed duct
- damage to the cells during a surgery
- genetic conditions, such as Gardner's syndrome or basal cell nevus syndrome
Small cysts are typically not painful. Large cysts can range from uncomfortable
to considerably painful. Large cysts on the face and neck may cause pressure
and pain. This type of cyst is typically filled with white flakes of keratin,
which is also a key element that makes up your skin and nails. Most cysts are
soft to the touch.
Areas on the body where cysts are usually found include:
A sebaceous cyst is considered unusual- and possibly
cancerous- if it has the following characteristics:
- a diameter that is larger than five centimeters
- a fast rate of reoccurrence after being removed
- signs of infection, such as redness, pain, or pus drainage
Most epidermoid cysts don't cause problems or need treatment. See your
doctor if you have one that:
- Grows rapidly
- Ruptures or becomes painful or infected
- Occurs in a spot that's constantly irritated
- Bothers you for cosmetic reasons
You can usually leave a cyst alone if it doesn't
cause discomfort or cosmetic problems. If you seek treatment, talk with your
doctor about these options:
- Injection: This treatment involves injecting the cyst with a
medicine that reduces swelling and inflammation.
- Incision and drainage: With this method, your doctor makes a small
cut in the cyst and gently squeezes out the contents. This is a fairly quick
and easy method, but cysts often recur after this treatment.
- Minor surgery: Your doctor can remove the entire cyst. You may need
to return to the doctor's office to have stitches removed. Minor surgery is
safe and effective and usually prevents cysts from recurring. If your cyst is
inflamed, your doctor may delay the surgery.
- Lasers: This method involves using a carbon dioxide laser to
vaporize the cyst. It results in minimal scarring.