ABSTRACT
Otitis media (OM) describes inflammation of the middle ear cleft. In the developed world, acute otitis media (AOM) and otitis media with effusion (OME) are the most common forms of OM, and are highly prevalent diseases in infancy and early childhood. AOM occurs due to ascent of resident bacteria from the nasopharynx up the Eustachian tube into the middle ear space, leading to a purulent middle ear effusion. The aetiology of AOM is complex, and relates to exposure of an individual to new virulent strains of bacteria individual susceptibility factors such as host genetics. AOM typically causes fever, malaise and unilateral otalgia. Many cases of OME occur following a preceding episode of AOM. However, some cases of OME occur de novo, for reasons that are incompletely understood, but may reflect subclinical infection of the middle ear. Otoscopy in OME reveals effusion deep to an intact tympanic membrane, imparting a blue or a yellow hue to the middle ear.
