Diseases of the middle ear account for approximately one third of office visits to pediatricians. The peak incidence of acute OM is between 6 and 15 months of life. By the first birthday, 62% of children experience at least one episode. Few first episodes occur after 18 months of age. OM is more common in boys and in patients of lower socioeconomic status. There is increased incidence of OM in Native Americans and Alaskan Natives and in certain high-risk populations, such as children with human immunodeficiency virus (HIV), cleft palate, and trisomy 21. In most of the United States, OM is a seasonal disease with a distinct peak in January and February, which corresponds to the rhinovirus, respiratory syncytial virus, and influenza seasons. The major risk factors for acute OM are young age, lack of breastfeeding, passive exposure to tobacco smoke, and increased exposure to infectious agents (day care).
As defined by the presence of six or more acute OM episodes in the first 6 years of life, at least 12% of children in the general population have recurrent OM and would be considered otitis-prone. Craniofacial anomalies and immunodeficiencies often are associated with recurrent OM; most children with recurrent acute OM are otherwise healthy.
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In infants, the most frequent symptoms of acute OM are nonspecific and include fever, irritability, and poor feeding. Inolder children and adolescents, acute OM usually is associatedwith fever and otalgia (acute ear pain). Acute OM also may present with otorrhea (ear drainage) after spontaneous ruptureof the tympanic membrane. Signs of a common cold, whichpredisposes to acute OM, are often present (see Chapter 102).A bulging tympanic membrane, air fluid level, or visualizationof purulent material by otoscopy are reliable signs of infection(Table 105-1).
Examination of the ears is essential for diagnosis and should be part of the physical examination of any child with fever. The hallmark of OM is the presence of effusion in the middle ear cavity (see Table 105-1). The presence of an effusion does not define its nature or potentially infectious etiology, but it does define the need for appropriate diagnosis and therapy.
Pneumatic otoscopy, using an attachment to a hermetically sealed otoscope, allows evaluation of ventilation of the middle ear and is a standard for clinical diagnosis. The tympanic membrane of the normal, air-filled middle ear has much greater compliance than if the middle ear is fluid-filled. With acute OM, the tympanic membrane is characterized by hyperemia, or red color rather than the normal pearly gray color, but it can be pink, white, or yellow with a full to bulging position and with poor or absent mobility to negative and positive pressure. The light reflex is lost, and the middle ear structures are obscured and difficult to distinguish. A hole in the tympanic membrane or purulent drainage confirms perforation. Occasionally bullae are present on the lateral aspect of the tympanic membrane, which characteristically are associated with severe ear pain.
Routine laboratory studies, including complete blood count and erythrocyte sedimentation rate, are not useful in the evaluation of OM. Tympanometry provides objective acoustic measurements of the tympanic membrane-middle ear system by reflection or absorption of sound energy from the external
A diagnosis of AOM requires: History of acute onset of signs and symptoms Presence of middle ear effusion Signs and symptoms of middle ear inflammation
The definition of AOM includes all of the following: Recent, usually abrupt, onset of signs and symptoms of middle ear inflammation and middle ear effusion The presence of middle ear effusion that is indicated by any of the following: Bulging of the tympanic membrane Limited or absent mobility of the tympanic membrane Air-fluid level behind the tympanic membrane Otorrhea
Signs or symptoms of middle ear inflammation as indicated by either: