Your Guide to Epidermoid Cysts

Medically Reviewed By Clare Wightman MS, PAC
Was this helpful?
0

An epidermoid cyst is a skin cyst that appears as a small bump filled with keratin. Epidermoid cysts are usually benign and tend to appear on the face, chest, and shoulders. You are most likely to develop an epidermoid cyst as a young or middle-aged adult. They occur two times as frequently in males than they do in females.

Read on to learn more about epidermoid cysts. This guide includes information about symptoms, causes, and treatments.

Key facts about epidermoid cysts

  • Epidermoid cysts are bumps on the skin that are filled with keratin.
  • You are more likely to have an epidermoid cyst on your face or trunk than elsewhere.
  • Males get epidermoid cysts two times more frequently than females.
  • They occur more frequently in young and middle-aged adults.
  • Blocked hair follicles are typically responsible for epidermoid cysts.

Read the full article for more information.

What is an epidermoid cyst filled with?

A man is looking at a laptop.
Dimitrije Tanaskovic/Stocksy United

An epidermoid cyst is filled with keratin and debris that is rich in lipids. Keratin is a protein that makes up hair, nails, and the outer layer of the skin.

The keratin inside the cyst can appear soft and yellow. In some cases, if an epidermoid cyst ruptures, the interior may be cheese-like and foul-smelling. Releasing keratin onto the skin and surrounding tissues can also result in inflammation.

What does an epidermoid cyst look like?

hg-epidermoid-cyst-neck-1296x728-body.jpg

Epidermoid cysts are characterized by a bump on the skin, often with a blackhead in the center.

Photography courtesy of Stevenfruitsmaak/Wikimedia

Infected,Sebaceous,Cyst

Epidermoid cysts are benign skin lesions that have a central blackhead, can grow slowly over time, and can sometimes drain.

Casa Nayafana/Shutterstock

Infected,Sebaceous,Cyst

Epidermoid cysts can become inflamed or infected and may be painful.

Casa Nayafana/Shutterstock

Where can an epidermoid cyst appear?

Epidermoid cysts typically appear on the face or trunk. However, they can appear anywhere on the body.

Epidermoid cysts commonly occur in the following places:

  • face
  • chest
  • shoulders
  • scrotum
  • vulva

Learn more about different types of cysts and where they can appear.

Is an epidermoid cyst the same as a sebaceous cyst?

Some people use the terms “epidermoid cyst” and “sebaceous cyst” interchangeably. However, it is important to note that they are not the same thing.

An epidermoid cyst is filled with yellowish-colored keratin. In contrast, a sebaceous cyst is filled with a clear oily liquid that is made by the sebaceous glands. True sebaceous cysts are less common than epidermoid cysts.

Learn more about sebaceous cysts.

What are the symptoms of an epidermoid cyst?

Epidermoid cysts are typically asymptomatic. However, you may experience related symptoms if the cyst ruptures.

Once an epidermoid cyst has ruptured, the keratin can cause inflammation of the surrounding skin. Other symptoms include:

  • tender to the touch
  • erythema (redness) on or around the ruptured cyst
  • swelling

How is an epidermoid cyst removed?

Most small and benign epidermoid cysts do not require removal. However, if a cyst is large and causing discomfort, you may wish to have it removed.

To remove the epidermoid cyst, the surgeon will perform a surgical excision to fully remove the entire cyst sac. If they remove the entire cyst lining, this decreases the risk of the cyst reoccurring.

If the cyst has ruptured and is inflamed, treatment typically involves a local injection of steroids to decrease the inflammation. Your surgeon will then carry out an excision once there is no inflammation.

Can I pop an epidermoid cyst?

You should avoid popping or bursting an epidermoid cyst. This can cause the cyst to become infected. If the cyst is infected, popping it can cause the infection to spread.

How is an epidermoid cyst treated?

Many cysts are small and benign, and they can resolve on their own without treatment. However, you may be able to speed up healing with home remedies and reduce the risk of any infections with over-the-counter medication. Your doctor may also prescribe medication if they are concerned that cellulitis will develop around a ruptured cyst.

Home remedies

It is important to avoid interfering with a cyst while it heals naturally. However, you may be able to speed up the healing process by holding a warm washcloth against the affected area of skin to bring the cyst to a head. You can also alternate a warm compress with a cool compress. The cool compress will reduce inflammation.

Medical treatments

If your epidermoid cyst has become infected, your doctor may prescribe antibiotics to alleviate symptoms. However, antibiotics are only needed in rare cases.

If a ruptured cyst has become inflamed, steroid injections into the lesion can decrease the inflammation.

If your doctor suspects that the cyst needs to be surgically removed, they may refer you to a dermatologist, which is a skin specialist.

What causes an epidermoid cyst?

An epidermoid cyst typically occurs due to a blocked hair follicle.

It may be possible for an epidermoid cyst to appear where there are no hair follicles, such as on the palm of the hand. This can occur if you experience an injury on the site without hair follicles, as epidermoid cells can enter the affected area.

How is an epidermoid cyst diagnosed?

Your doctor will typically not need to carry out any tests to diagnose an epidermoid cyst. However, if you are presenting other symptoms, they may decide to perform an ultrasound to further evaluate the soft tissue mass and to rule out other types of cysts or growths.

An ultrasound can also help to narrow down the diagnosis. Depending on the location of the cyst and other symptoms, other possible diagnoses include:

Learn more about how cysts are diagnosed.

What are the risk factors for an epidermoid cyst?

Anybody can get an epidermoid cyst, but they occur more often in young and middle-aged adults. They are also twice as likely to occur in males than in females.

Certain conditions may make you more likely to develop an epidermoid cyst. Conditions in which epidermoid cysts may occur include:

  • Gardner syndrome
  • pachyonychia congenita (type 2)
  • basal cell nevus syndrome

Are there any complications of an epidermoid cyst?

Complications may occur with an epidermoid cyst. If the cyst ruptures, complications can include:

  • erythema
  • swelling
  • pain

You may also experience complications following excision. These can include:

  • bleeding
  • infection
  • scarring

Summary

An epidermoid cyst is a skin cyst that is filled with yellowish-colored keratin. It is typically benign and usually occurs on the face, neck, shoulders, and chest.

Most epidermoid cysts do not require medical treatment or removal. However, for large or uncomfortable cysts, a dermatologist can perform a surgical excision to fully remove the cyst.

Epidermoid cysts are usually asymptomatic. However, you may experience swelling, inflammation, or tenderness if the cyst ruptures.

Contact your doctor if you are concerned about an epidermoid cyst. If necessary, they will be able to carry out an ultrasound for a closer look at the cyst.

Was this helpful?
0
Medical Reviewer: Clare Wightman MS, PAC
Last Review Date: 2022 Jul 8
View All Skin, Hair and Nails Articles
THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.
  1. Epidermoid and pilar cysts (previously known as sebaceous cysts). (2020). https://www.bad.org.uk/shared/get-file.ashx?id=198&itemtype=document
  2. Hoang, V. T., et al. (2019). Overview of epidermoid cyst. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6732711/
  3. Lam, M. (2020). https://dermnetnz.org/topics/epidermoid-cyst
  4. Skin cyst. (2020). https://www.nhs.uk/conditions/skin-cyst/
  5. Zito, P. M., et al. (2021). Epidermoid cyst. https://www.ncbi.nlm.nih.gov/books/NBK499974/