Mastoiditis

Mastoiditis is a pus-forming infection of the bone you can feel as a small lump just behind the ear. The infection gets there from the middle ear, almost always after an ear infection. The condition is uncommon but moves fast: only a few days separate "my ear aches a bit" from a situation that needs hospital care. Most cases happen in children under two. Mastoiditis is treated as an inpatient, and when help is sought in time it clears up without lasting damage.

The bone behind the ear and how pus reaches it

The mastoid process is the bump of the temporal bone sitting behind the ear. Inside it is not solid: the bone there is built like a honeycomb, from many air-filled cells divided by very thin partitions. All these cells connect to the middle ear cavity through a single narrow passage.

During a middle ear infection the lining that covers both the middle ear and the mastoid cells swells up. The narrow passage closes, and pus that used to drain away freely stays trapped inside the bone. Pressure rises, the bony partitions soften and dissolve, and the separate cells merge into one cavity full of pus. From that point it is no longer an ear infection but mastoiditis.

The pus then looks for a way out. It can break outwards under the periosteum and lift the skin behind the ear, it can track down into the muscles of the neck, or it can go the opposite way, into the skull, where the coverings of the brain and the large venous sinuses lie. That is why this illness does not tolerate a wait-and-see approach.

What it looks like and how it feels

The picture combines the signs of an ear infection with what is happening behind the ear. Usually there is:

• pain and tenderness on pressing behind the ear rather than inside it;
• redness and swelling of the skin over that spot; on brown and black skin the redness is harder to see, but the swelling shows just as clearly;
• the ear pushed forwards and downwards, so that the difference from the other side is obvious, especially looking at the person from behind or from above;
• a temperature that persists or has climbed again;
• discharge from the ear, or a damp patch on the pillow;
• reduced hearing and a blocked feeling on that side;
• headache, tiredness, irritability and loss of appetite.

A very young child cannot say where it hurts. In babies, watch for constant crying, refusing the breast or bottle, restless sleep and the way the child pulls at one ear or presses that side of the head against you. Look at the skin behind both ears in good light and compare the two sides.

How it differs from an ordinary ear infection

Telling them apart at home is not always possible, but a few pointers help.

In acute middle ear infection the pain is inside the ear and eases by the second or third day. In mastoiditis the pain moves behind the ear, to a spot you can point at with a finger, and it does not settle. The pattern over time is telling as well: the child had improved, the temperature had come down, and a few days later everything returns and is worse than before. That is the classic story.

The other giveaway is the protruding ear. An ear infection does not change the shape of the ear.

Antibiotics deserve a separate word. Mastoiditis can develop even while they are being taken, either because the organism is not sensitive to that particular drug or because the pus is already sealed inside the bone and the medicine cannot reach it. So "but she is already on antibiotics" is not a reason to wait: if swelling and tenderness appear behind the ear, the child needs to be seen the same day.

When to get emergency help

Call an ambulance (across Europe the single number is 112) or go to the emergency department if, alongside a sore ear, any of the following appears:

• severe headache with vomiting, discomfort in bright light, or an inability to bring the chin down to the chest;
• confusion, unusual drowsiness, a child who is hard to wake;
• a fit or seizure;
• the face pulling to one side: the corner of the mouth drops and the eye on that side will not close;
• double vision, severe dizziness with vomiting, unsteadiness on the feet;
• swelling and tenderness spreading down from behind the ear into the neck;
• in a baby, a bulging tense fontanelle, floppiness, grunting breathing, refusing feeds.

These mean the pus has left the bone. Waiting until morning, ringing a helpline or trying ear drops are not options here.

Without those signs, but with swelling and pain behind the ear, a red protruding ear or a temperature that will not settle after an ear infection, arrange to be seen the same day rather than leaving it until after the weekend.

Who is more at risk

Mastoiditis mainly affects children in the first two years of life: their mastoid cells are still forming, the passage between the middle ear and the mastoid is short and wide, and ear infections are common at that age. Repeated ear infections, antibiotic courses stopped halfway, weakened immunity and diabetes all raise the risk.

Mastoiditis in an adult deserves separate thought, particularly when there was no acute ear infection beforehand or when the ear has been discharging for months. Behind that pattern there is often a cholesteatoma: a growth of skin-type tissue inside the middle ear that slowly eats away at the bone from within. Less commonly the cause turns out to be tuberculosis, a rare form of blood vessel inflammation, or a tumour of the temporal bone. All of these change both the investigations and the treatment, and a course of antibiotics alone will not settle the matter.

How the diagnosis is made

It starts with examination. The doctor compares both areas behind the ears, judges how the ear sits, feels the bone, and then looks at the eardrum with an otoscope: in mastoiditis it is usually inflamed, bulging or already perforated. Movements of the face and eyes are checked.

The diagnosis is confirmed by a CT scan of the temporal bones, which is the only test that shows whether the partitions between the cells have been destroyed and whether the pus has escaped from the bone. A plain skull X-ray does not show this and is not worth the time. If complications inside the skull are suspected, an MRI scan with imaging of the venous sinuses is added, and where meningitis is a possibility a lumbar puncture is done.

Discharge from the ear, or pus obtained during surgery, is sent for culture and sensitivity testing, which allows the drug to be changed if the first choice was wrong. Blood tests cover the full blood count and inflammatory markers. Once the inflammation has settled, hearing is tested.

Why mastoiditis is dangerous

Complications are the main reason this illness is treated in hospital.

• An abscess under the skin behind the ear; if pus tracks beneath the neck muscles, a deep neck abscess forms.
• Weakness of the facial muscles on that side, because the facial nerve runs through the bone close by.
• Inflammation of the inner ear, with severe vertigo and permanent hearing loss.
• Clotting of the venous sinus that lies right against the mastoid, with a high swinging temperature and shivering.
• Meningitis and brain abscess, the most serious outcomes of all, and far from rare before antibiotics existed.
• Lasting hearing loss on the affected side.

All of this is uncommon today, and it happens mostly when getting help has been put off for weeks.

How it is treated

Treatment begins in hospital without waiting for the culture result. The mainstay is antibiotics given into a vein, at doses high enough to reach the bone and, if needed, cross into the coverings of the brain; the doctor chooses the drug and adjusts it when the sensitivities come back. The first days are spent watching the response: whether the swelling goes down and the temperature falls.

A small cut is often made in the eardrum and a ventilation tube inserted. This gives the pus somewhere to drain and brings quick relief. An abscess behind the ear is opened and drained.

If there is no improvement within two or three days, or if destroyed bone, a cholesteatoma or a complication is found, a mastoidectomy is carried out: through a cut behind the ear the affected cells are removed along with the pus. The operation sounds alarming but is generally well tolerated, and hearing is usually preserved.

Paracetamol or ibuprofen at a dose appropriate to age and weight will help with pain and fever. Ear drops achieve nothing on their own here: they do not reach the bone. Warm compresses, heat pads and any attempt to "draw out" the inflammation with heat are the wrong thing to do with pus in the bone.

After discharge, and reducing the chance of a repeat

The antibiotic course at home is finished to the last day, even once the person feels well: a half-treated infection in bone comes back. Attend the follow-up appointment, and have hearing checked a few weeks later. Some muffling after the infection is normal, but it is worth confirming that it has recovered.

After that, the main thing is not to let ear infections drift. If an ear has hurt for more than two days, the temperature persists or the ear starts to discharge, it needs to be looked at. When ear infections keep coming back, an ear, nose and throat specialist will discuss ventilation tubes. Vaccines against pneumococcus and Haemophilus influenzae type b are useful too: they cut the number of ear infections and with them the risk of mastoiditis. The ages at which they are given follow the national immunisation schedule of your country.

Simple measures help as well: no smoking indoors where a child lives, feeding a baby propped up rather than lying flat, and dealing with a nose that stays blocked for weeks instead of putting up with it.

Online consultation with a doctor

A remote appointment answers the key question well: is this an ordinary ear infection or is it time to go to hospital. The doctor will ask how things have changed day by day, ask for photographs of both ears taken from behind in good light, explain how to press on the bone behind the ear, weigh up the temperature and the child's behaviour, and say whether an ear, nose and throat specialist is needed today. Online is also a good place to go through a scan report or a culture result, understand why the antibiotic is being changed, and plan the follow-up after discharge: when to have hearing tested and who to see about repeated ear infections. If there is already swelling and redness behind the ear, or any of the signs listed under emergency help, an online appointment is not the right route: a face-to-face examination is needed, and for the severe signs an ambulance.

This material is for information only and does not replace medical advice.