How to say it

ehp-ih-DER-moid sihst

What causes an epidermoid cyst?

In most cases, epidermoid cysts occur for no known reason. Sometimes an epidermoid cyst may occur because of an injury to the skin or from acne.

Symptoms of an epidermoid cyst

An epidermoid cyst is a subcutaneous bump. This means it's just below the skin. It may be yellow or skin-colored. It often has a small black mark in the middle of it, like a blackhead.

An epidermoid cyst rarely causes pain, unless it breaks open (ruptures) or becomes inflamed or infected. It may ooze keratin, a white, cheesy, smelly material. If the cyst becomes inflamed or infected, it may be:

• Bad smelling

• Red

• Swollen

• Sore

Treatment for an epidermoid cyst

Many epidermoid cysts don’t cause any problems. They don’t always need to be treated. They may go away on their own. But you may want to treat it if you don’t like how it looks or it becomes inflamed. Or if it's in an uncomfortable place. Treatment options include:

• Steroid injection. A steroid may be injected into the cyst. This may help ease inflammation.

• Antibiotics. In some cases, you may need to take an oral antibiotic to treat infection and reduce inflammation.

• Surgical removal. The cyst can be cut out. Inflamed cysts are hard to remove. They may need to be drained or treated with antibiotics or steroids before surgery. There is a slight chance the cyst may come back.

When to call your healthcare provider

Call your healthcare provider right away if you have any of these:

• Fever of 100.4°F (38°C) or higher, or as directed by your provider

• Redness, swelling, or fluid leaking from your incision that gets worse

• Pain that gets worse

• Symptoms that don’t get better, or that get worse

• New symptoms