Sebaceous cysts, or skin cysts, are slightly hardened, fluid-filled bumps within the skin. They range from pea-sized, at about 1 centimeter across to around 5 centimeters across.
People often call these cysts sebaceous cysts, but this is not a correct medical term. The correct term is a skin cyst.
They can occur anywhere on the body, but they are often found on the face, neck, and torso.
They are non-cancerous and not life-threatening, but they can be uncomfortable.
Skin cysts do not usually cause any problems, apart from their appearance. They are not usually tender, but their presence can be obvious to the touch.
If a cyst on the scalp catches on a brush or comb, for example, this may cause pain, but cysts are normally only painful if they become inflamed or infected. Infections sometimes occur because the cyst has burst.
Most skin cysts do not need treating. The best course of action is simply to keep them clean and not interfere with them.
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.
Doctors are advised not to excise a cyst while it is inflamed, but to wait 4 weeks. During this time, it may resolve on its own.
To treat an infected cyst:
- apply a warm compress
- keep it clean by washing regularly with a mild, antimicrobial soap
- do not cover it with cosmetics
If you are concerned about an infected cyst, ask a health professional for advice. A doctor may prescribe an antibiotic.
Applying home remedies, such as tree oil, apple cider vinegar, and aloe vera, may help, but there is no research to confirm this.
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.
What does a cyst look like? Find out here.
It is not clear why skin cysts form. They develop when multiplying cells move 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.
Why skin cysts form is not understood. In some cases, there is a genetic link. Gardner's syndrome, for example, is a genetic disorder that is linked with skin cysts and 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.
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.
Most cysts do not develop complications, but the appearance may cause embarrassment.
Another possible complication is infection, if bacteria enter the cyst
Cysts are not fixed to anything deeper or below the skin, and the cyst and the area of skin around it can be moved.
Very rarely, a cyst can extend deeper into the body. It may be connected to underlying tissue.
A lump that is fixed and cannot be moved around needs to be seen by a doctor.