These are small lumps which develop underneath the skin on your body and possibly groin area although they are more commonly found on the neck and face. They are benign cysts which take a long time to grow and are usually painless.
An epidermoid cyst is also known as a sebaceous cyst, keratin cyst or epidermal inclusion cyst. But whether it should be known as a sebaceous cyst is open to debate as they are considered to be two separate cysts.
The sebaceous cyst is formed from oil (sebum) which is produced in the sebaceous glands. This oil helps to lubricate the skin and hair.
Epidermoid cysts are formed from cells which are found in the outer layer of skin or epidermis – hence the name.
Causes of epidermis cysts
The epidermis is the top layer of your skin. It is comprised of millions of tiny cells which are shed on a continuous basis. But that process fails in some way which pushes these cells deeper under the skin where they start to multiply. These cells then group together to form a cyst.
The cyst resembles a small lump or balloon which is filled with keratin – a protein found within the skin which has a thick, white or yellow appearance. This often discharges from the cyst.
They are caused by any of the following:
- Burst sebaceous gland
- Damaged hair follicle
- Genetic disorder, e.g. Gardner’s Syndrome
Anyone can get epidermoid cysts but there are people who are more at risk of doing so. These include:
- Men (more at risk than women)
- People who have suffered from acne
- People who have spent a long time in the sun
- People who have suffered from a hand injury
Plus adults are more likely to develop these cysts than children and teenagers.
Symptoms of epidermoid cysts
A cyst is a small, round ball which forms beneath the skin. These protrude through the skin and can be touched or moved with the finger. These cysts range in size from a quarter of an inch up to 5 centimetres.
They are white or yellow in colour and develop on the face, neck and body.
You may notice a tiny opening on a cyst which if pressed, will ooze a thick substance which has a foul smell. Avoid doing this as it increases the risk of an infection and scarring.
There may be redness, inflammation and soreness around the cysts.
Smaller types of epidermoid cysts are known as milia and occur due to prolonged sun exposure or heavy use of make up.
Complications of epidermoid cysts
These cysts are generally harmless but there are situations which require medical attention. See your GP if you notice any of the following complications with your cysts:
- Ruptured cyst/s
- A cyst will rapidly increases in size
- Painful cyst/s
- A cyst which develops in a highly sensitive part of the body
If you have a cyst which becomes sore due to constant friction from clothing then also see your GP.
Diagnosing epidermoid cysts
Your GP will be able to make a diagnosis from observing your epidermoid cysts. But he/she may refer you to a dermatologist if there are complications.
Treatment for epidermoid cysts
If you have a mild case of these cysts then they are usually left alone. This is fine for small cysts but larger, painful cysts which have become red and inflamed require treatment.
Treatment options include:
- Incision: a tiny cut is made in the surface of the cyst to enable the thick substance to drain away.
- Injection: corticosteroid injections into the cyst will reduce any swelling and soreness.
- Excision: the entire cyst is removed
- Laser: a laser is used to remove the infected cyst
Your GP or dermatologist will discuss these options with you.
Can you prevent epidermoid cysts? You cannot stop these from developing but there are a few ways in which you can reduce the risk. Limit the time you spend in the sun, use a suncream and choose non-oil based skin products instead.