Mastoiditis is a serious bacterial infection. It affects the mastoid bone behind the ear. It is more common in children.

Most people do not have any complications as long as you get diagnosed and treated quickly.

Symptoms of mastoiditis

The majority of cases follow an acute middle ear infection.

Symptoms of mastoiditis include:

  • redness, tenderness and pain behind the ear
  • swelling behind the ear that can cause it to stick out
  • discharge from the ear - this can persist even after antibiotic treatment
  • a high temperature, irritability and tiredness
  • headache
  • hearing loss in the affected ear

Urgent advice: See your GP as soon as possible if

you or your child have:

  • any symptoms of mastoiditis
  • an ear infection that doesn't clear up with treatment or is followed by new symptoms
  • been diagnosed with mastoiditis and treatment hasn't cleared it up

Causes of mastoiditis

The mastoid bone looks a little like honeycomb. The bone contains air spaces called mastoid cells.

You can get mastoiditis if the mastoid cells become infected or inflamed. This often happens if you have had a bad middle ear infection (otitis media).

Cholesteatoma can also cause mastoiditis. This is an abnormal collection of skin cells inside the ear. It can stop the ear draining. This can lead to infection.

Diagnosing mastoiditis

Your GP will examine the inside of the ear with an otoscope. An otoscope is a device with a light and magnifying glass.

If your GP thinks you have mastoiditis due to a middle ear infection, they'll refer you urgently to an Emergency Department (ED) or an Eye, Nose and Throat (ENT) specialist for more tests.

This usually includes a blood test and an ear culture test. An ear culture test is where discharge from the ear is tested for a bacterial infection.

Some children may need to have a CT scan. A CT scan uses x-rays and a computer to create detailed images of the inside of the skull.

Treating mastoiditis

Mastoiditis is a serious infection. It's important to get a diagnosis early and treat it with antibiotics.

You may need to go to hospital so you can get antibiotics directly into one of your veins, through a drip.

In some cases, you may need surgery to either:

  • drain the middle ear (a myringotomy)
  • remove part of the mastoid bone (mastoidectomy)

If you're admitted to hospital for treatment you'll need to stay in for a few days. You'll have to stay there until the ENT specialists can be sure the infection is under control.

After surgery

If you've had surgery for mastoiditis, you'll probably need to take a week or two off work.

Take care not to get the affected ear wet. You should be able to wash your hair after about a week, providing you do not get water inside your ear.

You should be able to go swimming around 4 to 6 weeks after the operation. But it depends on how well your ear has healed.

Your doctor should be able to give you specific advice after surgery. You'll also see them for follow-up appointments.

Complications of mastoiditis

Most people with mastoiditis do not get serious complications. But treatment is not always easy. The infection may come back.

Sometimes the infection in the mastoid bone is severe. If it is, and it is not removed, it can cause hearing loss. It can also cause life-threatening health complications such as:

  • a blood clot
  • meningitis
  • a brain abscess

Content supplied by the NHS and adapted for Ireland by the HSE

Page last reviewed: 22 December 2020
Next review due: 22 December 2023

This project has received funding from the Government of Ireland’s Sláintecare Integration Fund 2019 under Grant Agreement Number 123.