Acute Otitis Media

AOM: Definition & Epidemiology - Ear's Achey Breaky Start

• Definition: Acute inflammation of the middle ear; rapid onset of signs/symptoms (e.g., otalgia, fever, irritability).
• Epidemiology:
  • Peak incidence: 6 to 24 months.
  • One of the most common childhood infections.
  • Key risk factors: recent URI, daycare attendance, pacifier use, formula feeding, exposure to tobacco smoke.

⭐ Most cases of AOM occur in children aged 6 to 24 months.

AOM: Etiology & Pathophysiology - Bug Invasion

• Key Pathogens:
  • Bacteria: S. pneumoniae (most common), H. influenzae (non-typable), M. catarrhalis. 📌 Sad Hot Mess
  • Viruses: RSV, Rhinovirus, Influenza (often precede).
• Pathophysiology:
  • Eustachian Tube Dysfunction (ETD) → impaired middle ear (ME) drainage.
  • Viral URI → ME inflammation → pathogen reflux from nasopharynx.
  • Bacterial proliferation → suppurative effusion.

⭐ The most common bacterial pathogen causing AOM is Streptococcus pneumoniae.

AOM: Clinical Features & Otoscopy - The Ear Weeps

• Clinical Triad: Otalgia (ear pain), fever, hearing loss. Irritability in infants.
• Otorrhea if Tympanic Membrane (TM) perforates.
• Otoscopy:
  • TM: Erythematous, opaque, bulging.
  • Loss of light reflex & bony landmarks.
  • ↓ Mobility on pneumatic otoscopy.
  • Pus/fluid behind TM; purulent discharge if perforated.

⭐ A bulging tympanic membrane on otoscopy is a hallmark sign of AOM.

AOM: Diagnosis & Criteria - Spotting the Sickness

• AOM Diagnostic Criteria:
  • Acute onset (symptoms <48 hours).
  • Middle Ear Effusion (MEE) evidenced by ≥1 of:
    • Bulging tympanic membrane (TM).
    • Limited/absent TM mobility.
    • Air-fluid level behind TM.
    • Otorrhea.
  • Signs of acute middle ear inflammation (e.g., distinct TM erythema, otalgia).
• Key Finding:

  ⭐ Impaired mobility of the tympanic membrane on pneumatic otoscopy is a key diagnostic finding in AOM.

AOM: Complications - When It Gets Nasty

• Intratemporal (Within Temporal Bone):
  • Mastoiditis (most common suppurative)
  • Petrositis
  • Facial nerve palsy
  • Labyrinthitis
• Intracranial (Inside Skull):
  • Meningitis
  • Brain abscess (temporal lobe, cerebellum)
  • Lateral sinus thrombophlebitis (LST)
  • Otitic hydrocephalus
• Extracranial (Rare):
  • Bezold's abscess (spread to sternocleidomastoid)

⭐ Acute mastoiditis is the most frequent suppurative complication of AOM.

• Non-suppurative:
  • Hearing loss (conductive, sensorineural)
  • Tympanosclerosis

AOM: Management - Kicking the Infection

• Pain/Fever: Acetaminophen or Ibuprofen.

• Observation (48-72h): Option for non-severe AOM if:

  • Unilateral: 6 months - 2 years.
  • Unilateral/Bilateral: ≥2 years.

• Antibiotic Therapy Algorithm:

  ⭐ Amoxicillin (80-90 mg/kg/day) is the first-line antibiotic for AOM in most cases.

• Key Points:

  • Duration: 5-7 days (≥2y, mild-mod); 10 days (<2y or severe).
  • Recurrent AOM (≥3 episodes/6mo or ≥4 episodes/12mo): Consider tympanostomy tubes.

High‑Yield Points - ⚡ Biggest Takeaways

• Most common bacteria: Streptococcus pneumoniae, then H. influenzae (non-typable), M. catarrhalis.
• Peak age group: Infants and children aged 6 to 24 months.
• Key symptoms: Sudden onset otalgia, fever, irritability, and conductive hearing loss.
• Otoscopic findings: Bulging, erythematous tympanic membrane; impaired mobility and loss of light reflex.
• First-line antibiotic: Amoxicillin is preferred; consider amoxicillin-clavulanate for recurrent/resistant cases.
• Most common intratemporal complication: Acute mastoiditis.
• Most common intracranial complication: Meningitis.