Chapter 59 Otitis Media
PATHOPHYSIOLOGY
Acute otitis media (AOM) is an inflammation of the middle ear. Children 6 years of age and younger are at particular risk for acute otitis media because their eustachian tubes are shorter and more horizontal, and lack the cartilaginous support found in older children and adults. This allows the eustachian tubes to collapse, which causes negative pressure in the middle ear. In turn, there is impaired drainage of middle ear fluid and possible reflux of pharyngeal secretions into this normally sterile area. The eustachian tubes of infants and children with cleft palate or Down syndrome are also wider, so they remain open; this allows bacteria to travel easily from the nasopharynx into the middle ear, and this further predisposes such children to infection. Acute otitis media is the most common infection for which antibacterial agents are prescribed for children in the United States. Among childhood diseases, it is second in prevalence only to the common cold, accounting for 1 in 3 pediatric sick visits in this country and over 13 million annual prescriptions. Growing concerns about the rising rates of antibacterial resistance have prompted changes in the medical management of uncomplicated AOM. Two types of otitis media are common in clinical pediatrics: acute otitis media and otitis media with effusion.
Acute Otitis Media
Acute otitis media is characterized by fluid in the middle ear with signs and symptoms of ear infection (bulging eardrum usually accompanied by pain, or perforated eardrum, often with drainage of purulent matter). The pathogens most commonly associated with otitis media include Streptococcus pneumoniae (25% to 50% of cases), nontypeable Haemophilus influenzae (15% to 30% of cases), Moraxella catarrhalis (3% to 20% of cases), viruses, and certain anaerobes. In the neonate, gram-negative enteric organisms or Staphylococcus aureus may also be the causative organisms. Group A Streptococcus and S. aureus (2% to 3% combined) were less common causes of acute otitis media in the pediatric population during the 1990s. Chlamydia pneumoniae infections may also be seen, most frequently in children aged 8 to 16 months.
Otitis Media with Effusion
Otitis media with effusion is characterized by fluid in the middle ear without signs and symptoms of ear infection. No definitive causative agent has been identified, although otitis media with effusion is seen more commonly in children with allergies or viral upper respiratory infections, and in those recovering from acute otitis media.
INCIDENCE
1. Otitis media occurs most often in children between 3 months and 3 years of age; age ranges of peak incidence are 5 to 24 months and 4 to 6 years.
2. Of affected children, 70% have one episode by age 3 years, with one third having more than three episodes. The younger the child at the time of the first infection, the greater the chance of recurrent infections.
3. Boys have more ear infections than girls.
4. Children are more likely to experience repeated episodes if a parent and/or sibling also had ear infections.
5. Children with craniofacial conditions such as a cleft lip and/or palate and Down syndrome are also at greater risk. Of children with cleft palate, 50% have chronic otitis media before surgical correction.
6. Children placed in large group day care settings from an early age have greater exposure to all causative bacteria and viruses from other children.
7. Exposure to an area with high pollution and/or allergens and to winter or spring weather conditions presents risk and increases the incidence of ear infections.
8. Children exposed to passive (secondhand) cigarette smoke have a significantly higher rate of otitis media.
9. Infants who are bottle-fed, especially while lying down, experience more ear infections than breast-fed infants.
CLINICAL MANIFESTATIONS
Acute Otitis Media
1. Red tympanic membrane, often bulging with no visible bony landmarks, immobile to pneumatic otoscopy (application of positive or negative pressure pulse to middle ear using bulb insufflator attachment on otoscope)
2. Rapid onset of signs and symptoms such as complaint of ear pain (otalgia), excessive crying or fussiness, and ear pulling in preverbal child
3. Fever, ranging from 100° to 104° F (present in about one half of children)
5. Anterior cervical lymphadenopathy
6. Transient conductive hearing loss lasting at least 2 to 4 weeks after acute infection
