Epidermoid Cysts at U.S. Dermatology Partners

What Are Epidermoid Cysts?

Epidermoid cysts are small bumps that form beneath the skin. Epidermoid cysts are common. In fact, they are the most common type of skin cyst. Epidermoid cysts typically develop in areas with more hair, including the scalp, face, neck, and trunk. They are slow-growing and typically painless. Epidermoid cysts rarely cause any skin health issues, and they may not require treatment unless they are ruptured, infected, or begin to change over time.

Are There Different Types of Epidermoid Cysts?

There is only one type of epidermoid cyst. However, dermatologists and physicians may refer to epidermoid cysts as epidermal inclusion cysts, epidermal cysts, infundibular cysts, and keratin cysts. Additionally, epidermoid cysts are often misidentified as sebaceous cysts. A sebaceous cyst is lined with sebaceous glands, which secrete sebum oil to keep hair and skin moisturized, whereas epidermoid cysts occur on any part of the skin and normally develop from hair follicles.

Who Develops Epidermoid Cysts?

Epidermoid cysts develop when skin cells are trapped beneath the outer layers of skin and release keratin, a naturally occurring protein, into the cyst sac. This typically occurs when the skin or hair follicle is damaged and keratin and dead skin cells are unable to be shed naturally.

Anyone can develop an epidermoid cyst, but risk factors for the condition include:

• Most epidermoid cysts develop on post-pubescent individuals
• Men are more likely to develop epidermoid cysts than women
• Certain genetic disorders like Gardner Syndrome, Gorlin Syndrome, or Favre-Racouchot Syndrome may cause clusters of epidermoid cysts to form
• Taking certain medications, including BRAF inhibitors, Imiquimod, or Cyclosporine, may increase the risk for epidermoid cyst formation
• Frequently damaged skin

This type of cyst often seems to appear spontaneously, but actually, epidermoid cysts most often occur due to skin or hair follicle trauma (cuts, burns, etc.). The traumatic skin injury causes skin cells that would typically be shed to move into the deeper layers of skin and multiply. Over time, these epidermal cells form cyst walls (a sac) that contains the cyst. Keratin protein is secreted into this cyst sac, causing the epidermoid cyst to grow larger. Epidermoid cysts can also develop around hair follicles. When the follicle becomes irritated or damaged, the skin may heal over the follicle, trapping skin cells that should be shed inside, allowing them to multiply and form a cyst sac.

What Are the Symptoms of Epidermoid Cysts?

Epidermoid cysts look and feel like other types of cysts and are easily diagnosed by a dermatologist. Some of the common symptoms of epidermoid cysts include:

• A round, movable bump under the skin
• Often develops on the face, neck, chest, and back
• May have open comedones (blackheads) in the center of the cyst
• May seep or drain when bumped, producing a thick, white/yellowish discharge
• The cyst and any discharge may have a pungent odor
• Inflamed or infected epidermoid cysts may be red, swollen, tender, or painful

Epidermoid cysts that are growing or changing rapidly, located in a place that is frequently irritated, or that burst should be examined and treated by a dermatologist. Infection is the most common adverse effect of untreated epidermoid cysts, but in rare cases (about 1%), skin cancer may develop from the injured skin. It’s important to consult with your dermatologist if you notice any changes to your cyst.

What Treatments Are Available for Epidermoid Cysts?

During a consultation visit, your dermatologist will typically be able to diagnose an epidermoid cyst quickly through visual examination. In some cases, they may perform a biopsy to confirm the diagnosis and ensure the cyst is not an indicator of a more serious skin health concern.

Depending on the location, size, and the patient’s level of discomfort, the dermatologist may not recommend any treatment. These cysts do not pose a threat to the patient’s health, and they typically grow very slowly if at all. While the epidermoid cyst won’t usually heal completely on its own, it may become significantly smaller over time.

If the cyst is infected, inflamed, swollen, painful, or in a noticeable place like the face, your dermatologist may recommend one of the following treatment options:

• Antibiotic treatment – If the cyst becomes infected, you may be prescribed oral and/or topical antibiotics.
• Steroid injection – A solution of steroids is injected into the cyst to reduce swelling and inflammation.
• Draining – A small incision is made in the cyst and the contents are drained. In most cases, draining is recommended if a cyst is inflamed or infected. This will offer some immediate relief, but it may not be a permanent solution as the cyst sac may refill over time.
• Surgical removal – This is a minor surgery that involves removing the entire cyst and cyst wall or sac. When epidermoid cysts are surgically removed, it will usually prevent the cyst from refilling or becoming inflamed again. This procedure is usually not recommended if the cyst is infected or inflamed. Before beginning surgery, an inflamed cyst may be drained and a patient may need to undergo antibiotic treatment.

It’s important to avoid “popping” and draining the cyst on your own as this can lead to more severe inflammation. Additionally, your cyst is likely to grow back after draining, so it’s important to receive professional treatment.

Can Epidermoid Cysts Be Prevented?

It is not typically possible to prevent the formation of epidermoid cysts. However, you can take care to avoid injuries or infections that increase the risk for epidermoid cysts. If you do have an injury, infection, acne breakout, ingrown hairs, or other condition that may trigger the formation of an epidermoid cyst, treating the underlying condition may decrease cyst formation.

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