What is mastoiditis?

Mastoiditis is a rare ear infection

Mastoiditis is a bacterial infection that affects the mastoid, a delicate bone behind the ear and is the rarest of all ear infections. Its structure is similar to that of a honeycomb, helping to maintain air space in the middle ear. When it becomes infected or inflamed, the porous bone begins to break down, causing visible swelling.

Causes and symptoms of mastoiditis

Mastoiditis normally develops after a middle ear infection, where bacteria from the middle ear travels into the air cells of the mastoid bone. However, it can also be caused by cholesteatoma, an abnormal collection of skin cells in the middle ear that can cause extensive inflammation and spread of infection to the mastoid.

The symptoms can share similar signs to other ear infections, but with an increased visibility of evidence. It’s important to be aware of the warning signs: fever, irritability, lethargy, swelling behind your ear, redness and tenderness of your ear, ear discharge, but also a middle ear infection that seemingly hasn't gone away.

Mastoiditis caused by ear infections

The infection normally occurs as a result of a persistent middle ear infection, and can spread outside of the mastoid bone, causing multiple complications if you do not deal with it quickly. The infection is most common in children, although as an adult, you can be affected too.

If you or your child has recently suffered from a middle ear infection, take note of your doctor's advice and recovery recommendations to minimise the risks of developing mastoiditis.

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If you have any concerns, book an appointment at one of our clinics. Regular hearing checks is an important step in maintaining your overall health and wellness. Our online hearing test is a good place to start on your hearing health.

Mastoiditis diagnosis

If you suspect that you might have developed mastoiditis, we highly recommend that you seek the advice of a doctor as soon as possible. They will invite you for an initial ear examination, where they will look inside your ear to evaluate your ear's function and check for any inflammation.

If they suspect you have an infection, they may recommend further tests to confirm the diagnosis, which may include x-rays, blood tests and swabbed ear-fluid cultures. If your infection is thought to be severe, you may also be sent for a CT or MRI scan. In rare cases, it can develop into meningitis when the lining of your brain becomes inflamed.


If you suspect you have mastoiditis, contact your GP as soon as possible. Our experts will also be on hand should you need any additional support. For more information about other forms of ear infections, visit our otitis externa, otitis media or labyrinthitis pages. If you suspect that you may have some degree of hearing loss, we have a range of suitable hearing aids that you are welcome to explore.

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