Epidermal Cyst

(Epidermoid Cyst; Epidermal Inclusion Cyst; Epithelial Cyst; Keratin Cyst)

by Cynthia M. Johnson, MA

Definition

An epidermal cyst is a lump under the skin. It has soft, yellow matter inside. They often happen on the face, neck, chest, upper back, genitals, or behind the ears.

Causes

It may be caused by:

Blockage of a hair follicle by skin cells due to a skin injury
Damage to a hair follicle due to acne

Normal Skin Anatomy

Risk Factors

Acne and skin injuries raise the risk of this type of cyst.

Symptoms

Problems may be:

Small, dome-shaped lump beneath the skin
Foul-smelling, cheese-like material that may drain from the cyst
Redness or pain on or around the cyst

Diagnosis

You will be asked about your symptoms and health history. A physical exam will be done. This is often enough to make the diagnosis. You may be sent to a doctor who treats skin problems.

Treatment

The cyst may go away on its own. It may need to be treated when it causes problems. This can be done with:

Surgery to remove the entire cyst, including its contents and cyst wall
Incision and drainage to remove the cyst contents, though it may return in time

Antibiotics may be given to treat infection.

Prevention

There is no way to prevent an epidermal cyst.

RESOURCES:

American Academy of Dermatology
http://www.aad.org

Family Doctor–American Academy of Family Physicians
http://familydoctor.org

CANADIAN RESOURCES:

Canadian Dermatology Association
http://www.dermatology.ca

Health Canada
http://www.hc-sc.gc.ca

References:

Common benign skin lesions. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/common-benign-skin-lesions. Updated February 5, 2018. Accessed November 25, 2019.

Cysts. DermNet NZ website. Available at:
...(Click grey area to select URL)
Updated February 2016. Accessed November 25, 2019.

Moreno-Ramírez D, Ruiz-Villaverde R, et al. A. process of care for patients with benign cysts and tumors: Consensus document of the Andalusian Regional Section of the Spanish Academy of Dermatology and Venereology (AEDV). Actas Dermosifiliogr. 2016 Jun;107(5):391-399.

Last reviewed September 2019 by EBSCO Medical Review Board James P. Cornell, MD
Last Updated: 7/28/2020

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