ACUTE OTITIS MEDIA

Acute Otitis Media (AOM) is a medical condition that refers to the rapid onset of inflammation of the middle ear, usually due to bacterial or viral infection. This inflammation is often associated with the accumulation of fluid in the middle ear, known as middle ear effusion. It is one of the most common illnesses of childhood. AOM can present with a variety of clinical symptoms and signs, including ear pain, fever, irritability, decreased appetite, vomiting, and diarrhea. In infants and young children, AOM may be associated with pulling or tugging of the ear, difficulty sleeping, and changes in behavior.

How common is it?

AOM is most common in the first year of life, particularly in the second six months of life. By the age of three years, approximately 50-70% of all children will have experienced at least one episode of AOM. By the age of nine years, at least 75% of all children will have had at least one episode of AOM.

Recurrent AOM is defined as three or more episodes of AOM in six months or four or more episodes in a year. It is estimated that about 5% of children under the age of 2 experience recurrent AOM. Children who experience their first episode of AOM before nine months of age are at a higher risk of developing recurrent AOM, with a 1 in 4 chance of experiencing multiple episodes of AOM.

The incidence of acute otitis media (AOM) can vary with the seasonal incidence of upper respiratory tract infections (URTIs), which are common viral infections that can cause inflammation in the Eustachian tubes, leading to AOM.

Types of AOM

Shambaugh (1) et al classified AOM into 3 types based on etiology namely viral, bacterial and necrotizing. Bacterial otitis media is the most common type of middle ear infection, and it is typically caused by bacteria such as Streptococcus pneumoniae, Haemophilus influenzae, or Moraxella catarrhalis. Viral myringitis is a condition that can occur with or without otitis media, and it is caused by a viral infection of the eardrum. It is often characterized by the appearance of small blisters or lesions on the eardrum. Common pathogens include Respiratory Syncytial Virus, Influenza and Parainfluenza viruses, Rhino virus and Adeno virus.

Necrotizing otitis media is a rare but serious form of middle ear infection that is typically seen in young children who are severely ill or have a weakened immune system due to a systemic disease. It is characterized by death of tissue in the middle ear and surrounding structures, and usually caused by Beta Hemolytic Streptococci. It can lead to a range of complications, including chronic otitis media, meningitis, and facial nerve paralysis. Due to the severity of the condition, early recognition and prompt treatment of necrotizing otitis media is crucial to prevent long-term sequelae.

Treatment may involve the use of antibiotics, surgical debridement, and close monitoring for complications.

Why does it occur?

The pathogenesis, or the process of how AOM develops, can be described as follows:

1. Blockage of the Eustachian tube: The Eustachian tube connects the middle ear to the back of the nose. It is responsible for equalizing pressure between the middle ear and the outside world. In AOM, the Eustachian tube can become blocked, preventing air from entering or exiting the middle ear.

2. Accumulation of fluid in the middle ear: When the Eustachian tube is blocked, fluid can accumulate in the middle ear. This fluid can provide a medium for bacteria or viruses to grow and multiply, leading to infection.

3. Infection of the middle ear: Bacteria or viruses can enter the middle ear through the Eustachian tube and infect the fluid that has accumulated there. This can lead to inflammation and swelling of the middle ear, which can cause pain and discomfort.

4. Rupture of the eardrum: In some cases, the pressure from the accumulated fluid and inflammation can cause the eardrum to rupture. This can lead to drainage of pus or fluid from the ear, and may provide relief from pain and pressure.

Risk Factors

Children under the age of 2 are more likely to develop AOM, as their Eustachian tubes are still developing and are more prone to blockages.

Children who attend daycare or have older siblings are more likely to be exposed to viruses and bacteria that can cause AOM. Allergies can cause inflammation and blockages in the Eustachian tubes, which can increase the risk of developing AOM.

AOM is more common during the fall and winter months, when cold and flu season is in full swing. People with weakened immune systems, such as those with HIV/AIDS or undergoing chemotherapy, may be more susceptible.

Babies who are bottle-fed may be at a slightly higher risk of developing AOM than those who are breastfed, as breastfeeding provides some immunity against infections.

Exposure to secondhand smoke and a positive family history of AOM are also risk factors for developing AOM. It is important to note that these factors do not necessarily cause AOM, but may increase the likelihood of developing the infection.

Stages of AOM

The stages of AOM are as follows:

1. Hyperemia: In the initial stage of AOM, the middle ear becomes inflamed, which results in increased blood flow to the area. This causes redness, warmth, and mild to moderate ear pain.

2. Exudation: As the inflammation continues, fluid accumulates in the middle ear, which can cause hearing loss, a feeling of fullness in the ear, and more severe ear pain.

3. Suppuration: If the infection is not treated, it may progress to the suppuration stage, where pus forms in the middle ear. This can cause the eardrum to bulge and may result in the rupture of the eardrum, leading to drainage of pus from the ear.

4. Coalescence: In some cases, multiple areas of suppuration may form in the middle ear, leading to coalescence. This can increase the severity of the infection and may require more aggressive treatment.

It is important to note that not all cases of AOM will progress through all four stages, and some individuals may experience only mild symptoms or none at all.

Diagnosis

The diagnosis of acute otitis media typically requires the following criteria:

1. A history of acute onset of signs and symptoms.

2. The presence of middle ear effusion (MEE), which can be indicated by bulging of the ear drum , limited or absent mobility of the ear drum, the presence of an air-fluid level behind the ear drum, or otorrhea (drainage from the ear).

3. Signs and symptoms of middle ear inflammation, which may include distinct erythema (redness) of the ear drum, distinct otalgia (ear pain that interferes with normal activity or sleep), and/or other signs of inflammation, such as fever and irritability.

Investigations

Diagnostic tests that may be used to help diagnose and manage acute otitis media include

1. Pneumatic otoscopy: This is a technique used to examine the ear using a special instrument (an otoscope) that allows the examiner to visualize the ear drum and assess its mobility in response to changes in air pressure. This can help confirm the presence of middle ear effusion and determine the severity of the condition.

2. Tympanometry: This is a test that measures the compliance of the ear drum in response to changes in air pressure. This can help identify the presence of middle ear effusion.

3. Bacterial swab of otorrhea: This can be used to identify the type of bacteria causing the infection, which can help guide antibiotic treatment.

4. Tympanocentesis: This is a procedure in which a needle is inserted through the tympanic membrane to collect a sample of fluid from the middle ear. This fluid can then be analyzed for the presence of bacteria that can help guide treatment.

Management

Amoxicillin is often the first-line antibiotic of choice for AOM in children, with a recommended dose of 80-90 mg/kg/day in two divided doses for a duration of 10 days. This is based on clinical evidence showing that Amoxicillin is effective in most cases of AOM and has a low risk of side effects.

In cases of penicillin allergy, Cephalosporins can be used as an alternative. If a child has been treated with amoxicillin in the previous 30 days, the risk of antibiotic resistance may be higher, and Amoxiclav may be recommended.

In cases of recurrent AOM that are unresponsive to amoxicillin, a longer course of Amoxiclav is recommended. Decongestants and antihistamines are not generally recommended for the treatment of AOM, as they have not been shown to be effective in reducing symptoms or preventing complications.

Steroids are also not generally recommended for the treatment of AOM, as there is limited evidence for their effectiveness in reducing symptoms and they may increase the risk of complications.

Not all cases require antibiotics. Some children can be managed conservatively. The following table explains the criteria for prescribing antibiotics in AOM.

The American Academy of Otolaryngology, Head and Neck Surgery has given the following algorithm for the management of AOM. (2)

Complications

AOM is a common childhood infection that usually resolves without complications. However, in some cases, AOM can lead to more serious complications. Here are some potential complications of AOM.

1. Otitis media with effusion (OME): This is a condition where fluid remains in the middle ear space after the infection has resolved. OME can cause a feeling of fullness or pressure in the ear, temporary hearing loss, and difficulty with balance.

2. Acute mastoiditis: This is a rare but potentially serious complication of AOM where the infection spreads from the middle ear into the mastoid bone behind the ear. Symptoms of mastoiditis can include fever, ear pain, swelling, redness, and tenderness behind the ear. Treatment usually involves antibiotics and sometimes surgery.

3. Facial nerve paralysis: This is a rare but potential complication of AOM where the infection causes inflammation of the facial nerve, leading to weakness or paralysis of the facial muscles on one side of the face. This can cause facial drooping, difficulty with facial expressions, and sometimes difficulty with speech or swallowing. Treatment involves surgery to release the pus from the middle ear and antibiotics.

4. Meningitis: This is an inflammation of the membranes that cover the brain and spinal cord, which can occur if the infection spreads from the middle ear into the brain. Symptoms of meningitis can include fever, headache, stiff neck, and sensitivity to light. Meningitis is a medical emergency and requires prompt treatment with antibiotics and other supportive measures.

5. Brain abscess: This is a rare but potentially life-threatening complication of AOM where a collection of pus forms in the brain. Symptoms of a brain abscess can include headache, fever, confusion, seizures, and changes in mental status. Treatment usually involves surgery and antibiotics.

Are there ways to prevent it?

Here are some strategies that may help prevent AOM in children.

1. Vaccination: Certain vaccines, such as the Pneumococcal Conjugate vaccine and the Haemophilus influenzae Type B vaccine, can help prevent infections that can cause AOM. It's important to make sure that children receive all of the recommended vaccinations according to the Universal Immunization schedule.

2. Avoiding secondhand smoke: Exposure to secondhand smoke can increase the risk of AOM. It's important to keep children away from tobacco smoke and to avoid smoking in the home or car.

3. Breastfeeding: Breastfeeding can help protect infants against infections that can cause AOM. The American Academy of Pediatrics recommends exclusive breastfeeding for the first 6 months of life, followed by continued breastfeeding as complementary foods are introduced.

4. Avoiding bottle propping: Bottle propping can increase the risk of AOM by allowing milk or formula to flow into the middle ear. It's important to hold babies during feeding or to use a bottle holder that keeps the bottle at a 45-degree angle or to avoid bottle feeding altogether.

5. Addressing environmental factors: Exposure to environmental allergens, such as dust, pollen, and animal dander, can increase the risk of AOM in children who are susceptible to allergies. Addressing these factors, such as by using air filters or removing allergens from the home, may help reduce the risk of AOM.

It's important to note that AOM is a common childhood infection, and it may not always be possible to prevent it. However, by taking these steps, you can help reduce the risk of AOM and promote overall health and well-being for your child. Do reach out to Bangalore ENT Institute if you or your child is experiencing the symptoms of Acute Otitis Media.

Bibliography

1. Gopen Q. ACUTE OTITIS MEDIA. Glasscock-Shambaugh Surgery of the Ear. 2010:425.

2. Venekamp RP, Sanders SL, Glasziou PP, Del Mar CB, Rovers MM. Antibiotics for acute otitis media in children. Cochrane database of systematic reviews. 2015(6).