Snapshot A 9-month-old boy presents to your urgent care clinic for increased irritability. One week prior to presentation, the patient had an upper respiratory infection, which has since improved. Over the last day, the mother has noticed that the child has been tugging at his right ear, refuses to lie down on it, and has had a fever. There is right tympanic membrane erythema that is bulging and minimally mobile with pneumatic otoscopy. Introduction Definition middle ear infection Epidemiology Incidence peak of acute otitis media infection is between 6-18 months of age Risk factors immunocompromise viral upper respiratory tract infection family history Etiology Infectious Streptococcus pneumoniae (most common of the 3) nontypeable Haemophilus influenzae Moraxella (Branhamella) catarrhalis Viral respiratory syncytial virus rhinovirus adenovirus coronavirus influenza parainfluenza Pathoanatomy Pathogenesis typically, a viral upper respiratory tract infection leads to inflammatory changes to the respiratory mucosa of this aerated system edema leads to obstruction at the isthmus of the eustachian tube, which poorly ventilates the middle ear, creating negative pressure this results in secretions accumulating in the middle ear, which creates a favorable environment for microbial growth Anatomy the middle ear is an aerated system, which includes the mastoid air cells, eustachian tube, and the nares respiratory mucosa lines this system Presentation Symptoms nonspecific findings fever irritability headache poor oral intake and nausea otalgia (most common complaint) best predictor of acute otitis media Physical exam bulging or fullness of the tympanic membrane (TM) erythema of the TM possible perforation with otorrhea possibe absence of light reflex Studies Pneumatic otoscopy tympanic membrane bulging (most specific finding) poor tympanic membrane mobility tympanic membrane color is typically white or pale yellow Differential Otitis media with effusion differentiating factors tympanic membrane is retracted or in the neutral position tympanic membrane is amber or blue airfluid level or bubbles appreciated behind the tympanic membrane Treatment Medical observation for a 2-day period can be tried given high incidence of viral etiology amoxicillin indications patients must have low-risk for amoxicillin resistance in children < 6 months of age in children 6 months-2 years of age with unilateral or bilateral acute otitis media in children > 2 years of age who are toxic appearing, persistent otalgia (> 48 hours), or a temperature of ≥ 102.2°F (39°C) (> 48 hours) in children > 2 years of age who have bilateral acute otitis media or ottorhea comments in patients who are at risk for amoxicillin resistance, give amoxicillin-clavulanate in patients with an allergy to amoxicillin, give a macrolide or lincosamide high dose is needed to overcome altered penicillin binding protein made by S. pneumoniae amoxicillin-clavulanate can be used as a second-line, if treatment failure with amoxicillin can be used first-line if local resistance pattern to amoxicillin Complications Hearing loss Tympanic perforation Tympanosclerosis Cholesteatoma Mastoiditis Meningitis Epidural and brain abscess Cavernous sinus thrombosis