Definition

Acute Otitis Media (AOM) is characterized by inflammation or infection in the middle ear, typically presenting symptoms lasting only a few days. While it primarily affects children, adults can also develop AOM.

Causes

 Infection

AOM is triggered by bacterial or viral infections, often following upper respiratory tract infections such as colds, flu, or allergies. These infections can lead to blockage or swelling in the nasal passages, throat, and eustachian tube.

The eustachian tube is a narrow channel connecting the middle ear to the back of the throat. The end of the eustachian tube that ends in the throat can open and close and has several functions:

• Regulates air pressure in the middle ear
• Clears air in the ear
• Allows fluid drainage from the middle ear

Swelling of the Eustachian Tube

AOM occurs when the eustachian tube swells or becomes blocked, resulting in decreased air exchange, increased negative pressure in the middle ear, and fluid accumulation. This trapped fluid provides an environment conducive to bacterial growth, leading to ear infection symptoms.

The eustachian tube is shorter and more horizontal in young children than in older children and adults. This anatomical difference makes it harder for fluid to drain from the middle ear, increasing the likelihood of blockages and making young children more prone to AOM.

Swelling of the Adenoid Glands

The eustachian tube can also be obstructed due to swelling of the adenoid glands, which are part of the immune system and located near the eustachian tube's end in the upper back of the nose. Because the gland is located near the end of the eustachian tube, swelling of adenoid could block the eustachian tube and cause increased susceptibility to AOM.

Swollen and irritated adenoids are more common in children because their adenoids are bigger than in adults. Other factors contributing to eustachian tube blockage include sinus infections, exposure to cigarette smoke, and feeding while lying down, which is common in infants.

Risk factor

Risk factors of developing AOM include:

• Children aged 6 months to 3 years are more prone to AOM due to the underdeveloped size and shape of the eustachian tube and their immature immune systems.
• Children in daycare are more exposed to colds and ear infections compared to those who are not.
• Infants fed with a pacifier, especially while lying down, are more susceptible to AOM than those who are breastfed directly.
• AOM is more common in autumn and winter. Individuals with seasonal allergies are at higher risk during high pollen seasons.
• Exposure to bad air quality such as cigarette smoke or air pollution increases the risk of AOM.
• Changes in altitude and climate.
• Having had a cold, flu, sinus infection, or previous ear infection.
• Cleft Palate. Children with cleft palates have differences or oral structures that make it harder for the eustachian tube to drain fluid properly.
• Hereditary or genetic factors can also increase the risk of AOM in children.

Symptoms

Babies and children with AOM may exhibit the following symptoms:

• Fussiness and frequent crying in infants
• Toddlers clutching their ears and grimacing in pain
• Complaints of ear pain in older children, especially when lying down
• Sleeping difficulty 
• Ear pulling
• Headache
• Sensation of fullness in the ears
• Fluid discharge from the ear
• Fever with a temperature of 38⁰C or higher
• Decreased appetite
• Vomiting
• Diarrhea
• Imbalance
• Hearing difficulties

Adults with AOM may experience:

• Ear pain
• Fluid discharge from the ear
• Hearing difficulties

Diagnosis

Paediatricians can use one or several tests to diagnose AOM:

Otoscope

A paediatrician uses an otoscope with a magnifying glass and a light to examine the inside of the child's ear. The otoscope helps assess the presence of:

• Redness
• Swelling
• Bleeding
• Pus discharge
• Air bubbles
• Fluid in the middle ear
• Perforation or holes in the eardrum

Tympanometry

A tympanometry test involves using a small instrument to measure the air pressure in the child's ear. This test provides valuable information about the presence of fluid in the middle ear, the eardrum's motion, and the ear canal's volume.

Reflectometry

A small instrument that produces sound is used near the child's ear in a reflectometry test. By analyzing the sound reflected back, the doctor can determine if there is fluid in the ear.

Hearing test

A hearing test can be performed to evaluate whether the child has any hearing loss or decreased hearing ability due to AOM.

Management

Complications

While AOM typically resolves without complications, the infection can recur if risk factors or underlying causes persist. Temporary hearing loss may occur during the infection but should return to normal after treatment. 

Possible complications of AOM include:

• Recurrent ear infections
• Swollen adenoid glands
• Swollen tonsils
• Perforated eardrum
• Cholesteatoma (a cyst formed by trapped skin of the ear linings and earwax)
• Speech delays in children due to hearing loss from recurrent otitis media infections
• Rarely, mastoiditis (infection of the mastoid bone behind the ear) or meningitis (infection of the lining of the brain) could occur

Prevention

To reduce the risk of AOM, consider the following preventive measures:

• Frequently wash your child’s hands and toys to prevent the spread of germs that can cause colds or respiratory infections.
• Avoid exposure to cigarette smoke.
• Ensure your child receives the influenza and pneumococcal vaccines to prevent flu and pneumonia.
• Breastfeed your baby directly rather than using a bottle, if possible.
• Avoid giving pacifiers to babies.

When to see a doctor? 

Symptoms of AOM can mimic other ear conditions. An accurate diagnosis is crucial so patients can get prompt treatment. Consult a doctor if:

• Symptoms persist for more than one day.
• Symptoms appear in children under six months old.
• Severe ear pain is present.
• A baby or toddler has trouble sleeping or is irritable following a cold or other upper respiratory infection.
• There is discharge of fluid, pus, or blood from the ear.

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