Acute Otitis Media

What Is Acute Otitis Media?

Acute otitis media (AOM) is an infection of the middle ear, the space located behind the eardrum (tympanic membrane). The middle ear is normally filled with air and contains three small bones — the malleus, incus, and stapes — that transmit sound vibrations from the eardrum to the inner ear, where they are transformed into signals for the brain.

The middle ear connects to the back of the nose and throat through a narrow passage called the Eustachian tube. This tube has two important functions: it ventilates the middle ear, keeping the air pressure equalized on both sides of the eardrum, and it allows fluid from the ear to drain into the throat.

When the Eustachian tube becomes swollen or blocked — often because of a cold, sinus infection, or allergies — fluid builds up in the middle ear. This fluid is an ideal environment for germs, leading to an infection. That infection is what we call acute otitis media.

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How Otitis Media Occurs and Common Germs

The sequence leading to an ear infection usually begins in the upper airways:

• A cold or allergies cause swelling in the nose and throat.
• The swelling blocks the Eustachian tube.
• Fluid builds up in the middle ear, creating an environment where germs can grow.

The most common organisms (germs) responsible for AOM are:

• Bacteria:

  • Streptococcus pneumoniae (a leading cause of ear infections and also pneumonia).

  • Haemophilus influenzae (non-typeable strains that often resist certain antibiotics).

  • Moraxella catarrhalis.

• Viruses: These can either directly cause the infection or weaken the ear’s defenses so bacteria can flourish. Respiratory syncytial virus (RSV), influenza virus, and rhinoviruses (the common cold viruses) are often involved.

This combined viral-bacterial interaction explains why ear infections often appear just as a cold seems to be improving.

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Risk Factors for Developing Otitis Media

Some children and adults are more prone to developing ear infections than others.

Age is the strongest risk factor. Children between 6 months and 5 years old are particularly vulnerable because their Eustachian tubes are shorter and more horizontal, which makes it easier for germs to travel from the throat into the ear. Their immune systems are also still developing, making it harder to fight infections.

Other risk factors include:

• Daycare or group childcare: Increases exposure to colds and infections.

• Pacifier use beyond the first year of life: Sucking can affect pressure in the middle ear and contribute to infections.

• Active smoking and secondhand smoke: Smoke irritates the lining of the nose and throat, causing swelling and poor Eustachian tube function.

• Family history: A genetic predisposition may play a role in frequent infections.

• Allergies: These can cause chronic nasal congestion and fluid buildup.

• Craniofacial disorders: Children with cleft palate or other facial abnormalities may have Eustachian tubes that do not function properly.

Adults generally have fewer risk factors, but smoking, allergies, and frequent sinus infections can contribute to their risk.

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How Otitis Media Presents 

The way acute otitis media presents can differ between children and adults.

In children, symptoms are often less specific. Babies and toddlers cannot describe ear pain, so they may show it by:

• Tugging or pulling at the ear,

• Becoming unusually irritable or crying more,

• Having trouble sleeping,

• Running a fever,

• Eating less (because sucking or swallowing affects ear pressure).

• Sometimes, fluid or pus may drain out of the ear if the eardrum ruptures, which often relieves the child’s pain suddenly.

In adults, symptoms are usually clearer. They commonly report:

• A sharp earache,

• A feeling of fullness or pressure in the ear,

• Decreased hearing,

• Fever in some cases,

• Drainage of fluid from the ear if the eardrum perforates.

Because adults have fewer ear infections, when one does occur, doctors often look carefully for underlying causes such as sinus disease, allergies, or rarely, a growth in the nose or throat that blocks the Eustachian tube.

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Medical Evaluation

The diagnosis of otitis media is mainly clinical, meaning it is made by the doctor through history and examination.

History-taking includes asking about recent colds, duration and severity of symptoms, prior ear infections, and whether the patient has had recurrent episodes.

Physical examination is centered on looking into the ear with an otoscope, a small lighted instrument, or with a microscope. In otitis media, the eardrum often looks red, bulging, and immobile when a puff of air is applied. Sometimes, fluid levels or bubbles can be seen behind the eardrum. It's also important to examine the areas around the ear to make sure there is no spread of the infection to surrounding structures (cellulitis, mastoiditis, facial nerve paralysis). Examining the upper airway with a scope (camera) allows to see the Eustachain tube to make sure it's not obstructed.

Additional tests are not usually necessary, but in cases of recurrent infections, doctors may request:

• Tympanometry, which measures how well the eardrum moves. You can read more about this test here.

• Hearing tests, especially if there are concerns about speech or learning delays in children, or if there are concerns about spread of the infection to the inner ear leading to sensorineural hearing loss. Learn more about hearing tests here.

• Rarely, imaging studies if complications are suspected (scan or MRI).

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Treatment of Otitis Media

Treatment depends on the patient’s age, severity of symptoms, and whether the infection is a first or recurrent one.

Treatment depends on age, severity, and whether it is a first or recurrent infection.

In children:

• Observation ("watch and wait"): For mild cases, especially in children over 2 years, the doctor may wait 24–48 hours before prescribing antibiotics, since many infections resolve on their own.

• Antibiotics: If symptoms are severe, the child is young (less than 2 years-old), or the infection does not improve, antibiotics (commonly amoxicillin) are prescribed.

• Pain management: Acetaminophen or ibuprofen helps with fever and pain.

In adults:

• Observation ("watch and wait"): If there are mild symptoms and no immune concerns, it’s often safe to wait 24–48 hours while using pain relievers, nasal decongestants, and steroid  nasal sprays

• Antibiotics are more commonly prescribed right away, since research shows that adults face a higher risk of complications, often because they seek medical care later than children. 

• Pain relievers and nasal decongestants may help relieve pressure and Eustachian tube blockage.

Surgical option:

• For children or adults with recurrent or persistent infections, a myringotomy with tube placement (small ventilation tube inserted into the eardrum) can prevent repeated fluid buildup. You can read more about myringotomies in this article.

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Possible Complications

Most ear infections heal without problems, but complications can occur if infections are untreated or frequent.

• Temporary hearing loss is common due to fluid in the ear. If fluid persists for months, it can interfere with speech and learning in children.

• Permanent hearing loss (sensorineural): If the infection spreads to the inner ear (rare), this would lead to labyrinthitis and sometimes permanent hearing loss. 
  
  
• Facial nerve paralysis: Because the facial nerve passes through the middle ear, swelling from an ear infection can sometimes affect this nerve and lead to temporary facial weakness or paralysis. With timely treatment, most people recover fully, but placing a drainage tube in the ear is usually necessary.
  
  

• Perforated eardrum may occur if pressure builds up and the eardrum ruptures. It usually heals, but recurrent ruptures can weaken the membrane.

• Chronic otitis media with effusion: A condition in which there is persistent fluid once the active infection is resolved. Causes a sensation of ear fullness or pressure, and feels like you're hearing under water.
  
  

• Mastoiditis is a more serious infection of the bone behind the ear.

• Rare complications include the spread of infection to the brain, leading to meningitis or brain abscess, but these are very uncommon today with prompt treatment.

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Treatment of Recurrent Otitis Media

Recurrent otitis media is defined as:

• 3 or more infections in 6 months, or

• 4 or more infections in 12 months.

For these children or adults, treatment options include:

• Ear tubes (tympanostomy tubes): The most effective way to reduce infections. Help ventilate the ear and reduce fluid buildup

• Adenoidectomy: Removal of the adenoids (lymphatic tissue at the back of the nose) may be considered if they are enlarged and blocking the Eustachian tube. This is rarely necessary in adults.

• Antibiotic prophylaxis: Giving low-dose antibiotics over a longer period was common in the past, but is now used much less often due to concerns about antibiotic resistance.

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Prevention Measures

Preventing ear infections involves reducing exposure to risk factors and strengthening the immune system.

• Vaccinations play a major role. The pneumococcal vaccine and the yearly flu shot both reduce the incidence of otitis media.

• Breastfeeding for at least the first 6 months provides antibodies that help protect infants from infections.

• Avoiding smoking and secondhand smoke reduces irritation and swelling of the Eustachian tube.

• Good hygiene practices such as regular hand washing and minimizing contact with sick children in daycare settings help reduce colds.

• Pacifier use in young children should be limited after 12 months.

• Feeding position: Infants should be fed in an upright position rather than lying flat, which can allow fluid to enter the middle ear more easily.

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Conclusion

Acute otitis media is a common childhood illness, but adults are not immune. Although usually mild and treatable, it can cause significant discomfort and, if untreated, lead to complications. Understanding its causes, risk factors, and treatment options helps parents and patients know when to seek care and how to prevent recurrent infections. With vaccines, healthy habits, and, in some cases, surgical options, the burden of ear infections can be greatly reduced.