Epidermoid Cyst

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Images of Cyst, Epidermoid (Sebaceous Cyst)


Epidermoid cysts, sometimes known as sebaceous cysts (a misnomer), contain a soft "cheesy" material composed of keratin, a protein component of skin, hair, and nails.

  • Epidermoid cysts form when the top layer of skin (epidermis) grows into the middle layer of the skin (dermis). This may occur due to injury or blocked hair follicles.
  • The lesion may be asymptomatic, but rupture of the epidermoid cyst can result in significant discomfort.

Who's at risk?

Epidermoid cysts are a common lesion that affect people of all ages.

Signs and Symptoms

Epidermoid cysts can be located almost anywhere but are most common on the face, neck, scalp, or trunk.

  • A cyst appears as a dome-shaped, skin-colored growth that usually moves when touched and pressed upon. It may have a small opening in the center.
  • The cyst can be well-defined or irregular due to prior rupture, scarring, and regrowth.
  • If manipulated or infected, the cyst can become red and may be tender.

Self-Care Guidelines

None necessary. It is advised not to try to express the material within cysts as further inflammation and even infection may result.

When to Seek Medical Care

See your primary care physician or a dermatologist if a cyst becomes inflamed or painful.

Treatments Your Physician May Prescribe

  • Inflamed, non-infected cysts may be injected with steroids to reduce inflammation.
  • Incision and drainage can provide immediate reduction in the cyst. However, this is a temporary measure. After this treatment, a cyst will refill with the cheesy contents because the lining of the cyst has not been removed.
  • Cysts may be removed (excised) surgically.

Trusted Links

MedlinePlus: Skin ConditionsClinical Information and Differential Diagnosis of Cyst, Epidermoid (Sebaceous Cyst)


Bolognia, Jean L., ed. Dermatology, pp.1721-1723. New York: Mosby, 2003.

Freedberg, Irwin M., ed. Fitzpatrick's Dermatology in General Medicine. 6th ed, pp.778-781. New York: McGraw-Hill, 2003.