Acute Otitis Media (Middle Ear Infection)

How middle ear infections develop

The middle ear connects to the back of the nose through the Eustachian tube, which drains fluid and equalizes pressure. During a cold or allergy flare, the tube swells and blocks. Fluid collects behind the eardrum, and bacteria or viruses from the nose multiply in it. Pressure builds and the eardrum bulges, causing pain.

Children are more prone because their Eustachian tubes are shorter, narrower and more horizontal, their immune systems are still developing, and their adenoids can block the tube openings.

The main bacteria are Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis. Viruses cause some cases alone.

Symptoms

In babies and young children

• tugging, rubbing or holding the ear
• crying and irritability, especially lying down
• trouble sleeping
• fever
• poor feeding (sucking and swallowing hurt)
• vomiting or diarrhea
• fluid draining from the ear
• not responding to quiet sounds

In older children and adults

• ear pain, often sudden and severe
• a feeling of fullness or pressure
• muffled hearing
• fever
• discharge if the eardrum perforates, which usually brings quick pain relief

Risk factors

• age 6 months to 3 years
• group child care
• exposure to tobacco smoke
• bottle feeding while lying flat; breastfeeding is protective
• pacifier use beyond 6 to 12 months
• family history of ear infections
• winter season and frequent colds
• allergic rhinitis
• cleft palate and Down syndrome, which affect Eustachian tube function

Diagnosis

A clinician looks at the eardrum with an otoscope. AOM is diagnosed when there is:

• a moderately to severely bulging eardrum, or
• new discharge from the ear not caused by outer ear infection, or
• mild bulging with recent ear pain (under 48 hours) or an intensely red eardrum

A pneumatic otoscope puffs air at the eardrum. A healthy eardrum moves; one with fluid behind it does not. Tympanometry measures eardrum movement in older children.

Related conditions

Treatment

Pain relief for everyone

• Acetaminophen (paracetamol) or ibuprofen, at the right dose for the child's weight, following the label. Do not give aspirin to children or teenagers.
• A warm compress over the ear may help.
• Anesthetic ear drops can help briefly in older children, but not if the eardrum may be perforated.

Antibiotics or watchful waiting

Following the American Academy of Pediatrics guideline:

With watchful waiting, antibiotics are started if the child is not better within 48 to 72 hours. Some doctors give a "safety-net" prescription to fill only if needed.

Amoxicillin is the usual first choice. Amoxicillin-clavulanate is used if amoxicillin was taken in the past 30 days or the infection does not respond. Other antibiotics are used for penicillin allergy. Most courses last 5 to 10 days depending on age.

Recurrent infections and ear tubes

For children with frequent AOM (3 episodes in 6 months or 4 in a year with one in the past 6 months) and persistent fluid, an ENT surgeon may recommend tympanostomy tubes (grommets). These tiny tubes ventilate the middle ear and reduce infections.

Complications

Complications are uncommon but include:

• perforated eardrum, which usually heals within weeks
• persistent fluid and temporary hearing loss, which can affect speech in young children
• mastoiditis, infection of the bone behind the ear
• rare spread to the inner ear, facial nerve or brain (meningitis, brain abscess)
• cholesteatoma after chronic or repeated infection

Prevention

• Keep children up to date with pneumococcal and yearly flu vaccines.
• Breastfeed for at least 6 months if possible.
• Avoid exposure to tobacco smoke.
• Feed babies upright rather than lying flat with a bottle.
• Limit pacifier use after 6 months.
• Wash hands to reduce colds.

Frequently asked questions

What is acute otitis media?

It is a sudden infection of the middle ear, behind the eardrum, usually following a cold. Fluid builds up and becomes infected, causing ear pain, fever and a bulging eardrum. It is one of the most common childhood illnesses.

Do all ear infections need antibiotics?

No. Many ear infections clear on their own within 2 to 3 days. Babies under 6 months, young children with both ears infected, and anyone with severe symptoms or ear discharge usually get antibiotics. For others, doctors may suggest pain relief and watching for 48 to 72 hours.

How long does an ear infection last?

Pain and fever usually improve within 2 to 3 days, with or without antibiotics. Fluid behind the eardrum can last for weeks to a few months after the infection clears, which can briefly muffle hearing.

Are ear infections contagious?

The ear infection itself is not contagious, but the colds and viruses that lead to it are. Handwashing, vaccinations and keeping sick children home from child care help reduce the spread.

Can adults get acute otitis media?

Yes, though it is less common than in children. Adults may get it after a cold, sinus infection or flying with congestion. Symptoms include ear pain, muffled hearing and sometimes fever. Recurrent ear infections in adults should be checked by an ENT specialist.