An epidermoid cyst is a lump under the skin filled with keratin. They are slow-growing, painless lumps, they are also very common and rarely non-cancerous. 

An epidermoid cyst is often confused with a sebaceous cyst. A sebaceous cyst is less common and its contents consist of a clear, oily liquid. An epidermoid cyst results from damaged hair follicles or the outer layer of the skin. 

An epidermoid cyst has two features: the lining and the contents. The lining is made up of skin cells, which secretes keratin. And keratin is the material that makes up the hair and the outer layer of the skin.  



Epidermoid cysts are usually painless unless they become infected. Its main symptom is a small movable lump under the skin that becomes red and/or warm when inflamed. It can vary in size and can also occur in infants. Epidermoid cysts can appear anywhere in the body but are most typically found on the: 

  • Face 
  • Ears 
  • Neck 
  • Chest 
  • Upper back 
  • Scrotum 
  • Vulva 



An epidermoid cyst occurs when the hair follicle is blocked, and keratin which occurs naturally in skin cells is trapped below the skin. This could also develop due to trauma to the skin. Or could be caused by an underlying genetic disorder, such as Gardner syndrome. 



An epidermoid cyst can be left alone especially if they do not cause any problem at all. But medical professional could suggest removing it surgically if: 

  • it gets infected 
  • if they interfere with everyday life 
  • for cosmetic purposes 


But if your epidermoid cyst has these characteristics, see your doctor immediately: 

  • grows rapidly 
  • ruptures and becomes infected 
  • is in a spot that is constantly irritated 
  • bothers you for any cosmetic reason 
  • is in an unusual location, such as the fingers or genitalia 

It is important to note not to remove an epidermoid cyst at home, as it can result to other complications.  


An epidermoid cyst is mostly harmless. But you should see your doctor if they become infected and inflamed. It is best to see your Doral healthcare professional to receive a correct and proper diagnosis.