When to worry about a sebaceous cyst


Sebaceous cysts are common skin cysts that can appear anywhere on the body, but are most common on the head, back of the ears, neck, and trunk. They are believed to be the result of an obstruction in the hair follicle or an injury to the skin. Also, some genetic disorders, such as Gardner syndrome, can predispose a person to developing sebaceous cysts.

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Some confusion arises around sebaceous cysts, since these cysts contain keratin and not sebum (oil), because they originate in the outer layer of the skin ( epidermis ) and not in the sebaceous glands .

In fact, the real name for a sebaceous cyst is an epidermoid cyst, although many people, including healthcare professionals, continue to misuse the term sebaceous cyst. Since the term "sebaceous cyst" is still frequently used in the medical community, we will refer to the cyst as such in this article.

Sebaceous cyst on the scalp. Lester W. Bergman / Getty Images

Symptoms of sebaceous cyst

Sebaceous cysts are soft, painless bumps that grow slowly under the skin. They usually have a visible hole in the middle (called the center point) and can move freely when touched .

You can see keratin if the cyst becomes inflamed and ruptured. Keratin is a "pasty" or "cheesy" substance that can have an unpleasant odor.

Some sebaceous cysts remain stable in size over time, while others increase in size, which can be uncomfortable and painful, especially if the cyst becomes inflamed. To prevent infection, it is important not to touch or try to remove the substance inside the sebaceous cyst, although this can happen on its own.

Signs that may indicate a sebaceous cyst infection include:

  • Redness
  • Sensitivity
  • Increased temperature of the skin over the cyst (sensation of heat).


Sebaceous cysts for the experienced eye are usually easily diagnosed by their appearance. In some cases, a skin biopsy or culture may be required to rule out other conditions with a similar appearance.

For example, an abscess (a collection of pus under the skin) or a lipoma (a benign mass of fatty tissue) can resemble a sebaceous cyst. To make sure the diagnosis is correct, you should see your doctor for a formal evaluation.

Watch out

Sebaceous cysts usually go away on their own and are not dangerous. However, as mentioned, they can become inflamed, painful, and even infected.

Sometimes sebaceous cysts grow so large that they can interfere with daily life. In this case, surgical removal may be required and this procedure can be done in your healthcare provider's office.

Inflamed cysts can often be treated by a doctor, who injects a steroid into the cyst to soothe and shrink the cyst. However, if your healthcare provider suspects that the cyst is infected , they must make an incision and drain it to remove the infected material.

Because an infected cyst can be painful, your doctor will likely inject an anesthetic (such as 1% lidocaine) around the cyst to numb the area before draining it.

If an infected sebaceous cyst is not treated right away, the infection can spread to the surrounding skin. This is called cellulitis , a more serious condition that often requires oral antibiotics in addition to incision and drainage.

For complete surgical removal of a cyst, including the cyst wall, the healthcare provider usually waits until the cyst becomes inflamed or infected before resecting it, as recurrence of the cyst is much less common in this case.

In addition to excision (surgical removal of the cyst), a study published in the Archives of Plastic Surgery reports on CO2 laser treatment to remove sebaceous cysts with minimal scarring and a low recurrence rate. This can be a good option for people with cysts on the face or other visible areas.

Get the word of drug information

The big picture is that it is important to check with your doctor whenever you notice any type of growth, lump, or lump on your body. Although sebaceous cysts are benign, your healthcare provider should examine you to make sure there are no other more worrisome concerns.

Frequently asked questions

  • Bad idea. If a sebaceous cyst becomes large enough to be of concern or becomes infected, your doctor may inject it with a steroid, drain it, or remove it with surgery.

  • If it is small and does not hurt (which is the case with most of these cysts), it is best not to touch it. This will most likely go away without treatment. If it contains pus or hurts, you can try applying a warm, damp cloth to open it and wring it out.

  • A mixture of dead skin cells and a protein called keratin . If the cyst is infected, it may also fill with pus.

  • Consult with a dermatologist . As a skin specialist, you will have the experience to properly diagnose a sebaceous cyst, as well as the tools and knowledge to treat it if necessary.

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