Mastoiditis

What the mastoid is

The mastoid process is part of the temporal bone of the skull, felt as a bump behind the ear. Inside, it is honeycombed with air cells that connect to the middle ear. When the middle ear is infected (acute otitis media), these air cells often fill with fluid too. In most cases this clears with the ear infection. In mastoiditis, infection persists and starts to break down the thin bony walls between the air cells (coalescent mastoiditis).

Causes

• Spread of acute otitis media, the usual cause in children
• Bacteria: Streptococcus pneumoniae, Streptococcus pyogenes, Staphylococcus aureus, Haemophilus influenzae, and Pseudomonas in chronic disease
• Chronic ear disease and cholesteatoma: a skin growth in the middle ear that erodes bone, causing chronic mastoiditis in older children and adults

Risk factors

• age under 2
• frequent ear infections
• delayed or no treatment of an ear infection
• weakened immune system
• incomplete pneumococcal vaccination

Symptoms

• redness, swelling and tenderness behind the ear
• the ear pushed outward and forward (protruding ear)
• ear pain, often severe and throbbing
• fever, irritability and lethargy in children
• ear discharge
• hearing loss on that side
• headache
• in babies, the swelling may be above the ear

Complications

Because the mastoid lies near the brain, major blood vessels and the facial nerve, infection can spread:

Diagnosis

• Examination of the ear and the area behind it with an otoscope; the eardrum usually looks red and bulging.
• CT scan of the temporal bones with contrast: shows breakdown of mastoid air cells, abscesses and spread inside the skull.
• MRI if intracranial complications are suspected.
• Blood tests: white cell count, CRP, blood cultures.
• Culture of ear fluid to guide antibiotics.

Treatment

• Hospital admission with intravenous antibiotics, adjusted to culture results, followed by a course of oral antibiotics.
• Myringotomy: a small cut in the eardrum to drain pus, often with a ventilation tube (grommet).
• Abscess drainage if an abscess has formed.
• Mastoidectomy: surgery to clear infected bone, if there is no improvement with antibiotics within 24 to 48 hours, an abscess, cholesteatoma or intracranial complication.
• Pain relief and fluids.
• Treatment of complications such as anticoagulation for venous sinus thrombosis.

Outlook

With prompt treatment, most children recover fully. Hearing usually returns to normal once the infection clears, but hearing should be tested afterward. Complications are rare but serious, which is why early recognition matters.

Prevention

• keep children's vaccinations up to date, including pneumococcal and Hib vaccines
• seek care for ear infections that are severe or not improving after 2 to 3 days
• complete prescribed antibiotic courses
• have ongoing ear discharge or recurrent infections reviewed by an ENT specialist

Frequently asked questions

What are the symptoms of mastoiditis?

Mastoiditis causes redness, swelling and tenderness behind the ear, an ear that sticks out more than usual, ear pain, fever and sometimes ear discharge and hearing loss. In young children, irritability and lethargy are common.

Is mastoiditis serious?

Yes. It needs urgent treatment because infection can spread to the brain, facial nerve, inner ear or major blood vessels. With prompt hospital treatment using IV antibiotics, most people recover fully.

Can adults get mastoiditis?

Yes, though it is less common than in children. In adults it is more often linked to chronic ear infections or cholesteatoma. Swelling behind the ear, ear discharge and pain in an adult should be assessed promptly.

How is mastoiditis treated?

Treatment usually involves hospital admission for IV antibiotics, draining the middle ear through a small cut in the eardrum, and sometimes surgery (mastoidectomy) to remove infected bone. A CT scan helps decide whether surgery is needed.