ENT · Infectious Disease
The facts most likely to be tested
The most common bacterial pathogens causing Acute Otitis Media are Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis.
Diagnosis requires the presence of middle ear effusion and acute signs of inflammation, such as erythema or bulging of the tympanic membrane.
Pneumatic otoscopy is the gold standard diagnostic tool, demonstrating decreased or absent tympanic membrane mobility.
Amoxicillin is the first-line antibiotic treatment for patients who do not have a severe penicillin allergy.
High-dose amoxicillin-clavulanate is indicated if the patient has received amoxicillin in the last 30 days or has concurrent purulent conjunctivitis.
Observation is an appropriate initial management strategy for children aged 6–23 months with unilateral disease and mild symptoms, or children ≥2 years with mild symptoms.
Myringotomy with tympanostomy tube placement is indicated for patients with recurrent acute otitis media (3 episodes in 6 months or 4 episodes in 12 months).
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A 14-month-old male is brought to the clinic by his mother due to two days of fever and increased irritability. On physical examination, the child is tugging at his right ear. Pneumatic otoscopy reveals a bulging, erythematous tympanic membrane with decreased mobility. The child received a course of amoxicillin for a similar episode three weeks ago.
What is the most appropriate next step in management?
High-dose amoxicillin-clavulanate
The patient meets the criteria for AOM and requires a change in antibiotic coverage to amoxicillin-clavulanate because he received amoxicillin within the last 30 days, increasing the risk of beta-lactamase-producing H. influenzae.
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Etiology / Epidemiology
Most common in children 6-24 months due to eustachian tube dysfunction. Primary pathogens: S. pneumoniae, H. influenzae, M. catarrhalis.
Clinical Manifestations
Presents with otalgia, fever, and bulging, erythematous tympanic membrane. Otitis media with effusion lacks acute inflammatory signs.
Diagnosis
Diagnosis requires pneumatic otoscopy demonstrating decreased TM mobility and acute signs of inflammation.
Treatment
Amoxicillin is the first-line treatment. Do not use if penicillin-allergic with anaphylaxis; use macrolides or cephalosporins.
Prognosis
Most resolve spontaneously. Mastoiditis is the most feared complication; monitor for post-auricular erythema.
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Epidemiology & Etiology
Peak incidence occurs in winter months, often following a viral URI. Daycare attendance and bottle propping are major modifiable risk factors. S. pneumoniae remains the most common bacterial isolate, though H. influenzae prevalence has increased with widespread vaccination.
Pertinent Anatomy
The pediatric eustachian tube is shorter, more horizontal, and more compliant than in adults, impairing middle ear drainage. This anatomical predisposition facilitates the reflux of nasopharyngeal secretions into the middle ear space.
Pathophysiology
Viral URI causes mucosal edema, leading to eustachian tube obstruction and negative middle ear pressure. This creates a vacuum that draws nasopharyngeal pathogens into the middle ear. Bacterial proliferation results in purulent effusion and subsequent TM inflammation.
Clinical Manifestations
Patients present with deep ear pain, irritability, and fever. Physical exam reveals a bulging, opaque, or erythematous TM with loss of light reflex. Red flags include post-auricular swelling, mastoid tenderness, or cranial nerve palsies, suggesting mastoiditis or intracranial extension.
Diagnosis
The gold standard is pneumatic otoscopy, which assesses TM mobility. A diagnosis requires acute onset of symptoms, presence of middle ear effusion, and marked TM erythema or bulging. Tympanometry may be used as an adjunct to confirm the presence of fluid.
Treatment
First-line therapy is Amoxicillin (80-90 mg/kg/day). If symptoms persist after 48-72 hours or if the patient received amoxicillin in the last 30 days, switch to Augmentin (Amoxicillin-Clavulanate). Contraindications for amoxicillin include severe penicillin allergy; use azithromycin or cefdinir instead.
Prognosis
Most cases resolve within 7 days. Mastoiditis is the most serious complication, requiring IV antibiotics and potential surgical drainage. Persistent effusion beyond 3 months may require referral for tympanostomy tubes.
Differential Diagnosis
Otitis Externa: pain with tragal pressure
Otitis Media with Effusion: no acute inflammatory signs
Bullous Myringitis: vesicles on the TM
Impacted Cerumen: visualization of wax on exam
Referred Otalgia: normal TM exam (e.g., dental pathology)