What is the likelihood of infants developing ear infections and how are they treated?

Likelihood and Treatment of Ear Infections in Infants

Otitis media is extremely common in infants, with more than two-thirds of children experiencing at least one episode before 3 years of age, and more than one-third having three or more episodes. 1

Epidemiology and Risk Factors

Incidence by Age

• Highest incidence occurs in children 6-24 months of age 1
• By 12 months of age, 62% of children have had at least one episode of acute otitis media (AOM) 1
• Before 3 years of age, 50-85% of children will experience at least one episode 2

Risk Factors

• Male gender (significantly increased risk) 1
• Ethnicity (Native Americans, Canadian/Alaskan Eskimos have higher rates) 1
• Early occurrence of first episode 1
• Sibling history of recurrent AOM 1
• Not being breastfed 1
• Day care attendance 1
• Exposure to tobacco smoke 1

Microbiology of Ear Infections

The most common bacterial pathogens in AOM are:

1. Streptococcus pneumoniae (found in about one-third of cases) 1
2. Haemophilus influenzae (20-30% of cases, 90% nontypable strains) 1
3. Moraxella catarrhalis (7-20% of cases) 1

Viral infections frequently precede or accompany AOM, creating eustachian tube dysfunction that leads to middle ear fluid accumulation 3.

Diagnosis

Clinical Presentation

• Ear pain (rubbing, tugging, or holding the ear may indicate pain)
• Fever
• Irritability
• Otorrhea (ear discharge)
• Anorexia
• Sometimes vomiting or lethargy 2

Diagnostic Criteria

AOM is diagnosed in symptomatic children with:

• Moderate to severe bulging of the tympanic membrane OR
• New-onset otorrhea not caused by acute otitis externa OR
• Mild bulging with either recent-onset ear pain (<48 hours) or intense erythema of the tympanic membrane 2

Diagnostic Methods

Three methods are available to determine middle ear effusion:

1. Pneumatic otoscopy (standard technique)
2. Tympanometry (limited use in infants under 6 months)
3. Acoustic reflectometry 1

Treatment Approach

Children Under 2 Years

For infants under 2 years with AOM, immediate antibiotic therapy is recommended, especially for severe symptoms or bilateral infections. 1

Treatment algorithm:

1. Pain management should begin immediately regardless of antibiotic decision 2
2. Antibiotic therapy for:
   • All children under 6 months 1
   • Children 6-23 months with bilateral AOM or severe symptoms 1, 2
   • Children with high fever or severe earache 1

First-Line Antibiotic Choice

High-dose amoxicillin (80-90 mg/kg/day in two divided doses) is the first-line therapy unless the patient has taken amoxicillin for AOM in the previous 30 days or has concomitant purulent conjunctivitis 2, 1.

Alternative antibiotics:

• Amoxicillin-clavulanate: For patients who received amoxicillin in the past 30 days or have conjunctivitis 2, 1
• Cefdinir or azithromycin: For patients with penicillin allergy 2

Treatment Duration

• 8-10 days for children under 2 years of age
• 5 days for older children 1

Treatment Failure

If symptoms persist despite 48-72 hours of antibiotic therapy:

1. Reexamine the child
2. Switch to a second-line agent like amoxicillin-clavulanate 2, 3

Complications and Sequelae

Hearing Loss

• The most important complication of AOM and middle ear effusion
• Average hearing loss of 25 decibels when fluid is present in the middle ear 1
• Potential impact on speech, language, and cognitive development 1

Persistent Middle Ear Effusion

• Effusion persists for weeks to months after every episode of AOM 4
• Causes conductive hearing loss of varying degrees 4

Rare Complications

• Mastoiditis and other intratemporal/intracranial complications can occur but are uncommon in developed countries 1

Prevention Strategies

1. Vaccination:

   • Pneumococcal conjugate vaccines (PCVs) 1
   • Annual influenza vaccine 1, 2

2. Breastfeeding:

   • Exclusive breastfeeding until at least six months of age can reduce the risk of AOM 2

3. Reducing risk factors:

   • Minimize day care attendance when possible
   • Avoid tobacco smoke exposure 1

Recurrent Ear Infections

For children with recurrent AOM (defined as 3+ episodes within 6 months or 4+ episodes within one year with one episode in the preceding 6 months), tympanostomy tubes should be considered 2.

Long-term prophylactic antibiotics are generally discouraged for recurrent AOM 1.

Important Considerations

1. While antibiotics are commonly prescribed, microbiological data suggest that only one-third of patients with AOM actually require antibacterial therapy for resolution of symptoms 4.

2. Children with recurrent ear infections should be evaluated for possible immunodeficiencies, especially if they have other recurrent infections or failure to thrive 5.

3. Otitis media with effusion (fluid in the middle ear without acute symptoms) should not be treated with antibiotics, decongestants, or nasal steroids 3.