What is a sebaceous cyst?
A sebaceous cyst is a type of cyst that forms in the epidermis, the outermost layer of the skin. A sebaceous cyst is also sometimes called an epidermal cyst. It forms when a sebaceous gland, an oil-producing gland in the skin, becomes blocked. This creates a sac that fills with a fatty yellow substance that can resemble cottage cheese.
Sebaceous cysts can be present at birth or caused by skin trauma, swollen hair follicles, and high levels of testosterone. The primary symptom of a sebaceous cyst is a painless nodule or pale lump in the skin. Sebaceous cysts are very common. They are not cancerous and are generally not a serious condition.
In some cases, a sebaceous cyst can become infected. Seek prompt medical careif you have a sebaceous cyst or a lump on the skin that becomes tender, painful, red, or warm to the touch.
What are the symptoms of a sebaceous cyst?
A sebaceous cyst appears as a painless round bump in the skin. Sebaceous cysts vary in size, are generally pale colored, and are movable under the skin. Sebaceous cysts can occur anywhere on the body except on the palms of the hands and the soles of the feet. They tend to arise in places that are hairy, such as the scalp and the scrotum and chest in men. They are also common on the face, ears and arms.
Symptoms that might indicate a serious condition
Occasionally, a sebaceous cyst can become infected or develop into an abscess. Seek prompt medical care if you have any of the following symptoms:
Drainage from the cyst
Redness, inflammation and swelling of the cyst
What causes a sebaceous cyst?
A sebaceous cyst occurs when an oil-secreting gland (sebaceous gland) in the skin becomes blocked. This creates a sac that fills with a fatty yellow substance. Sebaceous cysts are more likely to occur if you have the following risk factors:
Hereditary tendency to form cysts (Gardner syndrome, Gorlin syndrome)
High levels of testosterone
Swollen hair follicles
How is a sebaceous cyst treated?
Because sebaceous cysts are generally harmless and cause no pain, they may require no treatment. Sebaceous cysts may also go away without any treatment or by simply applying a warm compress a couple of times a day to help the cyst to drain or reabsorb into the body.
Occasionally, a sebaceous cyst may become infected, or it may grow large enough to cause embarrassment or discomfort by rubbing on clothing or interfering with daily activities. In these cases, treatment of a sebaceous cyst may include:
Injection of corticosteroid medication into the cyst to reduce pain and inflammation
Oral antibiotic medication for a sebaceous cyst that is infected with bacteria
Surgical removal of the cyst, a minor procedure that can be done on an outpatient basis. A sebaceous cyst may come back if it is not completely removed.
If you have a sebaceous cyst, do not attempt to remove it, cut it open, or pop it. This can lead to an infection or inflammation. Seek medical care (call 911) if you wish to have it removed.
In some cases, a sebaceous cyst can lead to complications. Complications of a sebaceous cyst include:
Adverse effects of treatment
Embarrassment, especially if sebaceous cysts are large or are on a prominent area of the body, such as the face
Infection of the cyst
Rupture of the cyst with an inflammatory reaction
Scar at site of removal