What Is It?

A sebaceous, or epidermal, cyst is a small, movable lump under the skin. It forms when surface skin cells move deeper into the skin and multiply. These cells form the wall of the cyst and secrete a soft, yellowish substance called keratin, which fills the cyst. If the wall of the cyst is ruptured, the keratin is discharged into the surrounding skin, which causes irritation and inflammation.

The cyst may remain small for years, or it may continue to get larger. These cysts are rare in children but common in adults. Sebaceous cysts are not cancerous.

Symptoms

A cyst is a movable, dome-shaped, smooth-surfaced mass that varies in size from a few millimeters to several centimeters (from less than a quarter of an inch to more than 2 inches. Sebaceous cysts appear mainly on the face, ears, chest and back, but they can occur on almost any skin surface.

Diagnosis

Your doctor can examine the swelling and tell you if you have a cyst.

Expected Duration

A cyst may disappear on its own or remain indefinitely.

Prevention

There is no way to prevent sebaceous cysts.

Treatment

A sebaceous cyst usually does not need to be treated unless it is infected or is causing a cosmetic problem. Infected cysts usually are treated by draining the fluid and removing the shell that make up the cyst wall. You also may be treated with antibiotics if the skin around the cyst is also infected. If a cyst is causing irritation or cosmetic difficulty, your physician can remove it by making a small incision in the skin and emptying the contents of the cyst and its wall.

When To Call A Professional

If you have a new swelling on your skin that lasts for more than two weeks, contact your doctor, especially if it is painful.

Prognosis

The outlook for sebaceous cysts is excellent. Many cysts have no symptoms and some will go away on their own. Cysts can return. Draining cysts or removing them surgically usually does not lead to any complications or side effects.

Additional Info

American Academy of Dermatology

P.O. Box 4014

Schaumburg, IL 60168-4014

Phone: (847) 330-0230

Toll-Free: (888) 462-3376

Fax: (847) 330-0050

http://www.aad.org/