Table of ContentsView AllTable of ContentsSymptomsCausesDiagnosisTreatment
Table of ContentsView All
View All
Table of Contents
Symptoms
Causes
Diagnosis
Treatment
Epidermoid cysts are non-cancerous, balloon-like bumps that slowly develop under the skin. They are filled with a substance calledkeratinand can range in size from less than 1/4 inch to several inches wide. The cysts can sometimes rupture and drain a thick, yellow, foul-smelling fluid.
Epidermoid cysts can appear anywhere but are most often seen on the face, scalp, trunk, groin, and upper back.Though typically harmless, the cysts may require treatment if they become enlarged or infected.
This article describes the symptoms and causes of epidermoid cysts as well as how they are diagnosed, treated, and prevented.
Also Known AsEpidermal cystEpidermoid inclusion cystEpithelial cystFollicular infundibular cystInfundibular cystKeratin cyst
Also Known As
Epidermal cystEpidermoid inclusion cystEpithelial cystFollicular infundibular cystInfundibular cystKeratin cyst
Verywell / Brianna Gilmartin
What Are the Symptoms of Epidermoid Cysts?
An epidermoid cyst looks like a raised, round bump. Like all cysts, it is filled with fluid.
With an epidermoid cyst, you can usually feel the cyst wall and move the cyst around fairly easily under the skin. There may also be a small, pore-like opening on the surface of the skin.
Other symptoms of an epidermoid cyst include:
This photo contains content that some people may find graphic or disturbing.See PhotoDermNet/CC BY-NC-ND
This photo contains content that some people may find graphic or disturbing.See Photo
This photo contains content that some people may find graphic or disturbing.
DermNet/CC BY-NC-ND
When to See a Healthcare Provider
Epidermoid cysts usually don’t cause any problems, but you should see a healthcare provider if it is:
If the cyst wall ruptures, it can lead to an infection.
What Are the Symptoms of an Infection?
What Causes Epidermoid Cysts?
Epidermoid cysts are the most common type ofskin cyst. They occur when epidermal cells—those that make up the outermost layer of skin called theepidermis—don’t shed properly and move beneath the skin’s surface.
Epidermal cells produce a type of protein called keratin that makes up your skin, hair, and nails. When these cells are trapped beneath the skin, they will continue to produce keratin, leading to the formation of a fully contained, fluid-filled cyst.
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How Are Epidermoid Cysts Diagnosed?
If needed, anultrasound(which produces images using sound waves) can help visualize the structure, position, and size of the cyst. The cyst wall will be clearly seen on an ultrasound, while the center of the cyst will look like ground glass.
To confirm the diagnosis, the dermatologist may want to rule out other possible causes (differential diagnosis), including:
An in-officebiopsycan be performed to obtain a tissue sample for apathologistto examine under a microscope. When seen up close, the cells will look clumped, fibrous, and horn-like.
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How Are Epidermoid Cysts Treated?
An epidermoid cyst doesn’t usually have to be treated if small and painless.Even so, some people may want it drained for cosmetic reasons, especially if it is on the face.
If the cyst is especially large or inflamed, acorticosteroid(steroid) injection can help reduce swelling and redness. Kenalog (triamcinolone) is commonly used for this.
Oral antibioticsmay be prescribed if the cyst is infected (or to prevent infection following the cyst drainage).
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Epidermoid Cyst Removal
Your healthcare provider may recommend the removal of an epidermal cyst if it is severe, recurs (comes back), or is located in a place where is continually irritated (such as around the collar or where your glasses touch the skin of your ear). You may also request that a cyst be removed for cosmetic reasons.
To remove the cyst, your healthcare provider will first make an incision to extract the keratin content. The cyst wall will then be separated from the surrounding tissues and removed with a pair of forceps or tweezers. If the incision is large, stitches or surgical glue may be needed.
By removing the cyst in its entirety, the trapped epidermal cells will no longer produce keratin and the cyst will no longer recur.
Can You Pop an Epidermoid Cyst?You should not squeeze, pop, or cut an epidermoid cyst. While an epidermoid cyst may feel as if it is movable, it is firmly attached to surrounding tissues. Attempting to remove it yourself increases the risk of bleeding, infection, and permanent scarring.
Can You Pop an Epidermoid Cyst?
You should not squeeze, pop, or cut an epidermoid cyst. While an epidermoid cyst may feel as if it is movable, it is firmly attached to surrounding tissues. Attempting to remove it yourself increases the risk of bleeding, infection, and permanent scarring.
Summary
An epidermoid cyst is a common, harmless cyst filled with keratin. Small cysts usually don’t need to be treated. Sometimes a cyst will grow large and need to be drained. Treatment may also involve antibiotics or a corticosteroid injection.
You may want your cyst removed for cosmetic reasons or because it is large and irritating. To remove the cyst, your healthcare provider will first drain it and then remove the cyst wall. Never attempt to remove an epidermoid cyst on your own.
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5 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Cedars Sinai.Epidermoid Cysts of the Skin.
Hoang VT, Trinh CT, Nguyen CH, Chansomphou V, Chansomphou V, Tran TTT.Overview of epidermoid cyst.Eur J Radiol Open. 2019;6:291–301. doi:10.1016/j.ejro.2019.08.003
Cho Y, Lee DH.Clinical characteristics of idiopathic epidermoid and dermoid cysts of the ear.J Audiol Otol. 2017 Jul;21(2):77-80. doi:10.7874/jao.2017.21.2.77.
Kamyab K, Kianfir N, Dasdar Sh, Salehpour Z, Nasimi M.Cutaneous cysts: a clinicopathologic analysis of 2,438 cases.Int J Dermatol. 2020;59(4):457-62. doi:10.1111/ijd.14808
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