A cholesteatoma is a rare, abnormal collection of skin cells inside your ear.

If it is not treated, a cholesteatoma can continue to grow and damage the delicate structures deep inside your ear, such as the tiny bones and cochlea that are essential for hearing (see diagram, left). It can lead to:

• an ear infection, with discharge from the ear
• hearing loss, which can be permanent 
• damage to your facial nerve, leading to weakness in half your face
• dizziness, if the cholesteatoma damages the balance organ
• noises in the ear (tinnitus) 
• a brain abscess or meningitis (if the infection spreads into the inner ear and brain)

What are the warning signs?

A cholesteatoma may be painless but often causes the following symptoms:

• a persistent smelly discharge from the ear (because it is often infected)
• hearing loss in the affected ear

What is the cause?

A cholesteatoma can develop if part of the eardrum collapses because of problems equalising the pressure across it.

This occurs when the Eustachian tube is not working properly – this connects your middle ear to the back of your nose and normally opens with swallowing.

Normally, dead skin cells are shed from the ear, but when the eardrum collapses into a pocket, the dead skin cells collect here.

A cholesteatoma can also occur after the eardrum has been damaged through an injury, infection, or after any kind of ear surgery.

It is possible to be born with a cholesteatoma, although this is rare.

How is it diagnosed?

Your GP may diagnose or suspect a cholesteatoma after examining your ear with an otoscope – an instrument with a light and magnifying glass that allows doctors to see inside your ear.

Treatment

Your GP may prescribe a course of antibiotics and eardrops to treat any infection inside your ear.

Most people with a cholesteatoma should be referred to hospital so that the ear can be examined by an ear, nose and throat surgeon and, if necessary, cleaned under a microscope. You may require a CT scan to further investigate the extent of the disease.

In most cases the cholesteatoma should be removed with an operation, to reduce the risk of complications. This is usually performed under general anaesthetic and often takes several hours.

The surgeon generally makes a cut either behind or just in front and above your ear. As well as removing the dead skin cells, they may also need to remove some of the sponge-like mastoid bone (part of the skull behind your ear) and repair any hole in your eardrum.

The risks of surgery are similar to those of leaving the cholesteatoma untreated (for example, hearing loss, noises in the ear and dizziness), but generally the benefits of removing the cholesteatoma far outweigh the risks. You should discuss these risks with your surgeon. 

After surgery

You may need to stay in hospital overnight after the operation, and should plan to take up to two weeks off work. Your doctor will advise on this.

Self-care advice

Take care not to get your operated ear wet. You should be able to wash your hair after a week, providing you do not get water inside the ear (this can be avoided by plugging the ear with cotton wool coated with Vaseline).

Swimming should be avoided for about three months after surgery and you should check with your surgeon at your follow-up appointment when it is safe to swim.

It is generally recommended to avoid flying for four to six weeks after surgery.

Follow-up appointments

If your stitches are not dissolvable, these may need to be removed by your practice nurse after about a week.

Most people have a follow-up appointment in a clinic two to four weeks after the operation, when the dressings in your ear will be removed.

A cholesteatoma can come back, so you will need to attend regular follow-up appointments to monitor this. Many people will need a second operation about one year after their first, to check there is no cholesteatoma left behind.