Otitis Media, Acute (AOM)

Key Features

Essentials of Diagnosis

• Moderate to severe bulging of the tympanic membrane (TM) or new otorrhea not associated with otitis externa

• Mild bulging of the TM and less than 48 hours of otalgia (ear-holding, tugging, or rubbing in a nonverbal child) or intense erythema of the TM

• Middle ear effusion, proven by pneumatic otoscopy or tympanometry, must be present

General Considerations

• Bacterial or viral pathogens can be detected in up to 96% of middle ear fluid samples from patients with AOM

• Polybacterial infections are seen in up to 55% of cases, with bacterial and viral coinfections occurring in up to 70%

• Causative bacteria

  • Streptococcus pneumoniae and Haemophilus influenzae account for 35–40% and 30–35% of isolates, respectively

  • Moraxella catarrhalis causes up to 15–25% of cases in the United States

  • Streptococcus pyogenes is found more frequently in school-aged children than in infants

• Most common viruses associated with AOM

  • Respiratory syncytial virus

  • Influenza virus

  • Adenovirus

  • Human metapneumovirus

  • Enteroviruses

Clinical Findings

• Two findings are critical in establishing a diagnosis of AOM: a bulging TM and a middle ear effusion (MEE)

• The presence of MEE is best determined by visual examination and either pneumatic otoscopy or tympanometry

• In order to distinguish AOM from otitis media with effusion, signs and symptoms of middle ear inflammation and acute infection must be present

• Otoscopic findings specific for AOM include

  • Bulging TM

  • Impaired visibility of ossicular landmarks

  • Yellow or white effusion (pus)

  • Opacified and inflamed eardrum

  • Squamous exudate or bullae on the eardrum

Differential Diagnosis

• Otitis media with effusion

• Bullous myringitis

• Acute mastoiditis

• Middle ear mass

Diagnosis

• Pneumatic otoscopy

  • Can improve diagnostic ability by 15–25%

  • The largest possible speculum should be used to provide an airtight seal and maximize the field of view

  • When the rubber bulb is squeezed, the TM should move freely with a snapping motion; if fluid is present in the middle ear space, the mobility of the TM will be absent or resemble a fluid wave

• Tympanometry

  • Can be helpful in assessing middle ear status, particularly when pneumatic otoscopy is inconclusive or difficult to perform

  • Can reveal the presence or absence of a MEE but cannot differentiate between acutely infected fluid (AOM) and a chronic effusion (OME)

  • Measures TM compliance as well as volume of ear canal, which can help differentiate between intact and perforated TM

  • Standard 226-Hz tympanometry is not reliable in infants younger than 6 months;a high-frequency (1000 Hz) probe is used in this age group

Treatment

• Pain management

  • Mild to moderate pain should be treated with ibuprofen or acetaminophen

  • Severe pain should be treated with opioids, but careful and close observation is required to address possible respiratory depression, altered mental status, gastrointestinal upset, and constipation

  • Topical analgesics have a very short duration and studies do ...