Tutorial - Keratosis Obturans and External Canal Cholesteatoma
These are unusual conditions of the outer ear canal but you will see them from time to time.
This is an abnormal accumulation of plugs of keratin in the bony part of the outer ear canal. There is no known cause for it. It is commoner in young adults and a half of patients have it in both ears.
Symptoms and Signs
The patient may complain of mild to severe ear pain with a decrease in their hearing due to keratin build up. Examination will reveal thick layers of dead skin in the deeper parts of the ear canal and there may well be associated inflammation of the skin. The ear canal, once cleaned, may appear to be wider than normal.
The images show the disease deep in the ear canal and the inflammation of the skin that is associated with them.
The best treatment for you to offer is repeated cleaning of the dead skin in the ear canal. You can treat and associated skin infection with topical antibiotic drops as you would for otitis external and this infection should respond quickly.
Sometimes, if the canal plug is very dense and painful to remove, a short general anaesthetic is useful to clean the ear. This can be offered by the local ENT Surgeons.
External Ear Canal Cholesteatoma
You are used to the idea of skin growing into the middle ear cleft an causing a cholesteatoma. In external canal cholesteatoma this doesn't happen. Instead, there is erosion and exposure of bone in the outer ear canal.
This is a very unusual disease and may follow canal trauma such as that caused by ear surgery and radiation treatment for cancers in the back of the nose or parotid.
Symptoms and Signs
These are usually unilateral and cause mild pain. Examination will find the skin of the floor of the ear canal to be irregular and inflamed and there may be exposure of bone. Small areas of skin buildup at the site can also be seen.
The images show exposed ear canal bone and the inflamed, irregular appearance of canal cholesteatoma
A CT scan is usually performed to see how extensive the canal cholesteatoma is.
The CT scan shows a soft tissue mass (the external canal cholesteatoma) just lateral to the tympanic membrane and erosion of bone (black arrows)
The first step is to diagnose the condition by examination and cleaning the ear. Topical antibiotics can be used to calm any associated infection butt hey are not a long term cure.
These ears require surgery and they should be referred to the local ENT Surgeon for excision and grafting of bone in the outer ear. Such surgery is often repeated as the condition may return.