In general, sebaceous cysts do not need treating. The best course of action is simply to keep them clean and not interfere with them.
They range from pea-sized, at about 1 centimeter across to around 5 centimeters across.
There are several types of skin cysts, including:
- Epidermoid cyst - the lining of the fluid-filled sac is formed by cells from the skin surface.
- Pilar cysts - the lining is made up of cells like those in the roots of hairs.
- Sebaceous cysts - these sacs contain oil, while regular skin cysts do not. They arise from the sebaceous glands in the skin.
Other types of fluid-filled sac, such as boils and abscesses can cause problems. However, cysts tend not to be as big or painful. In most cases, no treatment is needed unless the cyst becomes infected.
Contents of this article:
Sebaceous cyst: What does it look like?
Sebaceous cysts appear as dome-shaped, raised areas on the skin.
A skin cyst is a nodule - a dome-shaped, raised area on the skin. Sometimes these cysts have a point at the top called a punctum, which may be a black spot.
The raised bump of a cyst feels harder than normal skin. The cyst and the area of skin around it can be moved like normal skin. This is because cysts are not fixed to anything deeper or below the skin.
A lump that is fixed and cannot be moved around needs to be seen by a doctor.
A skin cyst is usually flesh-colored, but could have slight whitening or yellowing to it.
Sebaceous cyst symptoms
Skin cysts do not usually cause any troublesome symptoms beyond the effect of their appearance and unattractive contents.
Skin cysts are not usually tender, but their presence can be obvious to the touch. Cysts on the scalp might catch on a brush or comb, for example, causing pain.
Cysts are only likely to give pain if they become inflamed or infected. Infections sometimes occur because the cyst has burst. If a cyst becomes infected, it can be painful.
What is a sebaceous cyst made of?
Both epidermoid and pilar cysts are filled with a substance that is like toothpaste in consistency, and cheesy and smelly. It is made of keratin, a protein found in skin and hair.
Microbes, like bacteria, do not normally infect the substance, but if they do infect it, the pus smells worse.
True sebaceous cysts, which are not seen as often as epidermoid and pilar cysts, contain a greasy substance; this is the oil that comes from sebaceous glands surrounding the base of normal hairs.
How do you get a sebaceous cyst?
How skin cysts form is easier to answer than why. Skin cysts form when multiplying cells moving inward, rather than moving to the surface and shedding away as skin cells normally do.
The epidermis is the top layer of the skin, and the outermost layer of the epidermis is where skin cells eventually shed away. Underneath the epidermis is the dermis layer.
Epidermoid cysts are when cells from the upper surface layer form a sac down in the lower layer.
Why skin cysts form is not understood. In some cases, there is a link to genetics. Gardner's syndrome, for example, is a genetic disorder linked with lots of skin cysts, along with other types of growth. Pilar cysts linked with hairs on the head may have an inherited tendency.
Skin cysts can sometimes form because of damage that causes top-layer cells to be "implanted" in the lower layer.
Sebaceous cyst treatments
Sebaceous cysts that cause problems should be looked at by a doctor.
While skin cysts can look bad, doing anything to them can make them worse:
Picking, rubbing, or squeezing cysts is likely to cause damage and make any infection worse. It is also likely to increase the pain and worsen its appearance.
Dealing with skin cysts that are causing concern or producing symptoms means getting them seen by a doctor.
Doctors can help make sure of the correct diagnosis and deal with any other concerns. They can also treat a troublesome cyst without making it worse.
The only appropriate home treatment for cysts is to keep infected ones clean. If a plain cyst is removed because it was causing problems, the area should also be kept clean.
People can keep a cyst clean at home by using a clean cloth, cotton wool, or medical dressing material. This should be used to help bathe the cyst gently with clean, warm water, and then to dab it dry.
If a cyst is not causing any trouble, there is no good reason for a doctor to intervene.
A doctor may remove a cyst if it is causing problems. This might be because of infection, because the cyst gets in the way of normal actions, or because it is in a prominent location.
Cyst removal at a doctor's office involves:
- local anesthetic to numb the area
- antiseptic procedures to avoid creating or spreading infection by preparing the skin area, and using a drape and sterile kit
- using a blade and other instruments to cut the cyst out
If a cyst has burst or there is an infection under the skin, the doctor may need to lance and drain it. A course of antibiotics may also be needed.
Tiny cysts can also be treated by lancing and draining.
Doctors removing a cyst will aim to remove it completely. If part of the sac wall is left behind, the cyst may form again.
Removing a cyst can leave a small scar. Cysts that do not cause any problems can safely be left alone without treatment.