An epidermal inclusion cyst (sebaceous cyst) is a fluid-filled lump under your skin. A keratin substance fills this cyst. It usually doesn’t cause symptoms. Don’t try to pop or remove an epidermal inclusion cyst. A healthcare provider will offer treatment to remove it if it causes discomfort.
An epidermal inclusion cyst (epidermoid cyst) is a fluid-filled pocket under the surface of your skin. It looks and feels like a lump or bump on your skin.
Many people call epidermal inclusion cysts “sebaceous cysts.” The term “sebaceous cyst” is misleading because the cyst isn’t filled with sebum. Sebum is an oily substance created by your sebaceous glands that keeps your skin moist. Instead, a keratin (protein) and cell debris substance fill epidermal inclusion cysts.
Most healthcare providers only use the term “sebaceous cysts” when associated with the skin condition known as steatocystoma multiplex. Cysts that form with this condition fill with sebum, so they’re truly “sebaceous cysts.” True sebaceous cysts aren’t common, but epidermal inclusion cysts are.
As the name implies, epidermal inclusion cysts form under the top layer of your skin (epidermis).
Epidermal inclusion cysts are the most common type of skin cyst.
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An epidermal inclusion cyst may have the following features:
A keratin and cell debris substance fills epidermal inclusion cysts. When drained by a dermatologist, this substance looks thick and yellow and has a foul odor.
An epidermal inclusion cyst isn’t usually painful (asymptomatic). Sometimes, the cyst can inflame (swell) and feel tender when you touch it. As the cyst grows, you may experience skin irritation and pain if it ruptures (breaks open). Occasionally you’ll experience itching at the site of an epidermal inclusion cyst. See your healthcare provider if you develop pain on or near a cyst or have other concerning symptoms.
Epidermal inclusion cysts can form anywhere on your body, but they’re most common on your:
Epidermal inclusion cysts form after a blockage to a hair follicle (an opening in your skin where hair grows out) at the follicular infundibulum (the top part of the hair follicle).
Your body naturally sheds skin cells when they reach the end of their life cycle. If you have a skin injury like a scratch, surgical wound or a skin condition like acne or chronic sun damage, it can disrupt the path your skin cells take to leave your body. This traps these cells and other components like keratin, so they collect under the surface of your skin. This is how a cyst forms.
On areas of your body where you don’t have hair follicles, a cyst can form after an injury or trauma to your skin, too. The injury pushes your skin cells below the top layer of your skin into the second layer (dermis). This creates a pocket where keratin collects and forms a cyst.
Although they can appear at any age, epidermal inclusion cysts most frequently occur between ages 20 to 60. Epidermal inclusion cysts rarely appear before puberty. They’re more common among people assigned male at birth (AMAB) than people assigned female at birth (AFAB).
Some rare genetic conditions and other conditions lead to the development of multiple epidermal inclusion cysts:
Certain medications may increase your risk of developing epidermal inclusion cysts, including:
No, epidermal inclusion cysts aren’t contagious.
Complications of an epidermal inclusion cysts may include:
Epidermal inclusion cysts are rarely harmful. However, researchers found rare cases where malignancy (cancer) formed within the cyst, specifically:
An epidermal inclusion cyst may be concerning if it has any of the following characteristics:
Talk to your healthcare provider if you notice changes to your skin.
A healthcare provider can diagnose an epidermal inclusion cyst during a physical exam simply by looking at it and learning more about your symptoms if you have any.
Although not usually necessary, testing can confirm a diagnosis. It may include:
If you notice changes to your skin, contact a healthcare provider. You might start with a primary care physician (PCP), and they can refer you to see a dermatologist or a doctor who specializes in skin conditions. Only certain providers can remove epidermal inclusion cysts. Your provider may refer you to a specialist trained to remove cysts, such as a dermatologist, general surgeon or plastic surgeon.
In many cases, a healthcare provider may recommend monitoring the epidermal inclusion cyst and not treating it if it doesn’t cause symptoms.
If the cyst swells and/or causes discomfort, use a warm compress over the cyst to reduce symptoms at home. If your symptoms continue or get worse, contact a provider. They may recommend removing it or they’ll inject a steroid medication into the cyst to temporarily reduce swelling.
Antibiotics can treat an inflamed or infected epidermal inclusion cyst.
Your provider may remove the epidermal inclusion cyst with the following procedures:
Don’t try popping or draining the cyst yourself. This could cause an infection, and the cyst will likely grow back (recur).
Risks of surgical excision of a cyst are rare but may include:
Epidermal inclusion cysts typically form randomly. However, avoiding injury or trauma to your skin and treating skin conditions may be helpful to reduce your risk.
Once you have a diagnosis, you can wait and see if the cyst improves on its own or discuss treatment options with your healthcare provider.
Most cysts don’t cause symptoms. But, it can be challenging if your cyst forms on a very visible part of your body, like on your face or scalp, or if it causes pain. Talk to a healthcare provider about cyst removal if the cyst is bothersome.
Some cysts decrease in size, while others continue to grow until you get treatment. Without treatment, you may have the cyst for the rest of your life.
Epidermal inclusion cysts sometimes remain small in size and asymptomatic for several years. However, they can also increase in size and may become uncomfortable or irritated. If the cyst bothers you, discuss treatment options with your healthcare provider.
Always see your healthcare provider if you find a lump on your skin. It might be an epidermal inclusion cyst, another type of cyst or something else. Don’t try to diagnose it yourself. See your healthcare provider for a clear diagnosis and specialized treatment.
You may want to ask your provider:
Most epidermal inclusion cysts aren’t dangerous. They’re usually asymptomatic. Not all epidermal inclusion cysts become infected, but infection is possible. Infections can be dangerous if left untreated. While very rare, some cysts can turn into cancer, so contact a healthcare provider if you notice changes to your skin.
A note from Cleveland Clinic
You may feel scared or anxious after finding a new lump or bump on your skin. The lump may be a harmless epidermal inclusion cyst or it may be a more serious diagnosis. Contact your healthcare provider as soon as you notice changes to your skin. They’ll give you an official diagnosis and answer any questions or concerns you have.
Treatment isn’t always necessary with epidermal inclusion cysts, but you may feel more comfortable if a provider removes it. Don’t try popping or draining the cyst at home. This could lead to an infection. Your healthcare provider will drain the cyst safely, so you don’t have to worry.
Last reviewed by a Cleveland Clinic medical professional on 11/15/2023.
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