Curriculum · ENT, Ophthalmology, and Dermatology
Acute otitis media
What it is
Acute otitis media begins with obstruction of the Eustachian tube. Air is absorbed in the middle ear, so the pressure becomes negative, an irritant to the middle ear mucosa; the mucosa develops edema with an exudate or effusion, and the exudate is then infected from nasopharyngeal secretions. It stands against otitis media with effusion, fluid in the middle ear with no signs or symptoms of infection.
Chronic otitis media is the other end of the same story: an ear with a tympanic membrane perforation in the setting of recurrent or chronic ear infections. Benign is a dry perforation without active infection, and chronic serous otitis media is continuous serous drainage, straw-coloured.
Causes and risk
The bacterial causes are S. pneumoniae, H. influenza in refractory cases, M. catarrhalis, Group A Streptococcus and S. aureus. The viral causes are RSV, influenza, parainfluenza and adenovirus.
The predisposing factors are Eustachian tube dysfunction or obstruction, from URTI, rhinosinusitis, allergic rhinitis, a nasopharyngeal tumor, adenoid hypertrophy or barotrauma; cleft palate; an abnormal horizontal Eustachian tube, as in Down's syndrome and Apert syndrome; disrupted cilia, as in Kartagener syndrome; and immunosuppression. The risk factors are day care or a crowded home, smoking and air pollution, a family history of otitis media, prematurity, lack of breast feeding, and a pacifier.