Epidermoid (Sebaceous) Cysts

What are Epidermoid Cysts?

Epidermoid cysts are small bumps that can develop anywhere beneath the skin. They are most commonly found on the trunk, face, and neck, and they are benign.

An epidermoid cyst will grow slowly and will usually be painless. Rarely will these types of cysts cause any problems or require any treatment. However, they can be removed by your doctor if they become infected, rupture, or are painful.

Although often referred to sebaceous cysts, epidermoid cysts are different. This is because a sebaceous cyst comes from a sebaceous gland that secretes an oily material designed to lubricate the skin and hair.

What are the Symptoms of Epidermoid Cysts?

An epidermoid cyst will be a round, small bump underneath your skin. You may notice a small blackhead that plugs the opening to the cyst, and there may also be a foul-smelling, thick, yellow discharge.

Other symptoms include swelling, tenderness, and redness around the cyst can occur if it becomes infected or inflamed.

Epidermoid Cysts Causes

A frequent cause is genetics. The altered gene KRT17 is passed on in an autosomal dominate pattern, meaning an individual parent is the carrier with a 50% chance of affecting a child. Sometimes, the offspring may not exhibit any signs of the disorder, but as a carrier, they will pass the inherited trait on to the next generation. If both parents are carriers of the mutated gene, the risk of developing this condition increases for the offspring.

In most situations, the condition develops deep under the skin’s surface, building up overtime. The condition can start with no family history, induced by an irritation to the oil gland, an injury to the skin or the hair follicle.

In rare instances, epidermoid cysts may form as a complication after a surgery. Trauma can lead to a blockage in the oil gland or its duct, forming a cyst sac, accumulating the yellowish keratin fluid. The severity and size of the cysts vary, depends on the underlying conditions.

How are Epidermoid Cysts Treated?

You should see your doctor if an epidermoid cyst ruptures, is infected or painful, or grows quickly. You can also contact your doctor to remove an epidermoid cyst if you don’t like the appearance of it on your skin.

Prior to removing a cyst, your doctor may give you antibiotics in order to reduce swelling. Your doctor can then remove this type of cyst by making a small incision and draining its contents, or by removing the entire epidermoid cyst through a minor surgery.

Another treatment option is an injection of medicine into the cyst that will reduce inflammation. Also, a carbon dioxide laser may be utilized in order to vaporize an epidermoid cyst.

Epidermoid Cysts Prevention

There is no prevention to stop epidermoid cysts from forming, but there are treatments and medications to prevent the infections. If you have a family history of the condition, you should talk to your doctor. It’s important to have your doctor review the family’s pattern of the condition and the underlying causes reported in your family’s medical records, to prevent recurring episodes.

If you are a carrier of this inherited trait, take the time to learn more about the condition, educate your own family and keep the medical records updated. If you discover a large lump accompanied with pain, you need to see your doctor at once for an accurate diagnosis. Do not try to treat this condition on your own; it may lead to more serious health issues.

Last Reviewed:
October 05, 2016
Last Updated:
December 19, 2017