Acute Otitis Media: Pathogenesis and Clinical Findings (in Children) Upper Respiratory Tract Infection: - Bacterial: Streptococcus pneumoniae (SP) (40-50%), haemophilus influenzae (25%), moraxella catarrhalis (10%). - Viral (25%): Respiratory syncytial virus, influenza, rhinovirus. - Non-tvpeable: 25-45%. - 2/3 both bacterial and viral. Bilateral AOM mostly bacterial. => Inflammation & edema of respiratory mucosa of the nose, nasopharynx, and eustachian tube => Obstruction of the eustachian tube isthmus => Obstruction results in accumulation of secretions normally produced in middle ear => Air from middle ear is resorbed into the circulation creating negative pressure => Negative pressure in the middle ear pulls viruses and bacteria into it, infecting and inflaming the middle ear => Most (75-80%) resolve by 72 hours Complications of AOM: TM perforation, hearing loss, mastoiditis, febrile seizures, abscess (see relevant slide for full mechanisms) #OtitisMedia #pathophysiology #diagnosis #symptoms #signs #peds #pediatrics
