Also called a skin cyst or an epidermoid cyst, a sebaceous cyst is a smooth lump that forms under the skin due to inflammation of a hair follicle. The cyst contains a yellow, cheesy material composed of dead skin cells and sebum.
Sebaceous cysts most commonly occur on the scalp, face, neck, body, and genitals. Although harmless, the cysts occasionally become very large and unsightly.
If a cyst becomes infected, it may become painful and may eventually burst. A cyst that is not causing problems does not need treatment.
A large, painful, or infected cyst may be surgically removed.
Antibiotics may also be prescribed for an infected cyst.