Cholesteatoma - Causes

Why does a cholesteatoma develop?

The cause of a cholesteatoma is quite difficult to explain, and even now is not fully understood.

We all have skin inside our ear canal. It is meant to be there and is a normal part of our ear. But with a cholesteatoma the skin right next to the eardrum, deep in the ear, gets sucked in gradually to where it shouldn't be. No one quite knows why this happens but it is usually related to the eardrum being very retracted (drawn inwards, deeper than it is meant to be).

This skin then forms a tiny pearl, or ball, that keeps burrowing its way deeper into the ear over many months. It damages the delicate bones inside the middle ear - the bit that is responsible for hearing.  At this point it becomes painful.

If left untreated it will push further and further inside the ear, through the inner ear and possibly even next to the brain. In the western world it would be very unusual for it to get that bad but this can happen in the developing world.

There are two types of cholesteatoma:

  • Congenital cholesteatoma: is a problem that in theory happens from birth. For some reason, even though the eardrum is normal, tiny skin cells get sucked into the middle ear, blocking the Eustachian tube. This then causes long-term fluid in the middle ear (which is usually free of fluid) and can cause hearing loss. This becomes apparent between the ages of 6 months to 5 years when the child's hearing doesn't develop properly. This is a very rare condition and the cause isn't fully known.
  • Acquired cholesteatoma: develops later, usually in adults between 30 and 50 years old. Again, the cause isn't fully known. Sometimes a cholesteatoma in an adult can happen from having a grommet - a tiny tube that is put through the eardrum as a treatment for middle ear problems - as a child.

The true occurrence rate of cholesteatoma is not known. About 1 in 1,000 people with ear problems referred to ENT clinics have cholesteatoma. It has also been suggested that there is about 1 case per 10,000 population. Most cases are of the acquired type.

Did you find this information useful?

Thanks for your feedback!

Why not subcribe to the newsletter?

We would love to hear your feedback!

Dr Oliver Starr
Peer Reviewer:
Dr Helen Huins
Document ID:
13267 (v4)
Last Checked:
09 May 2017
Next Review:
29 June 2020

Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of medical conditions. Patient Platform Limited has used all reasonable care in compiling the information but make no warranty as to its accuracy. Consult a doctor or other health care professional for diagnosis and treatment of medical conditions. For details see our conditions.