OME is defined as the presence of fluid in the middle ear without signs or symptoms of acute ear infection.The condition is common enough to be called an ‘‘occupational hazard of early childhood’’ because about 90% of children have OME before school age 5, and they develop, on average, 4 episodes of OME every year. Synonyms for OME include ear fluid and serous, secretory, or nonsuppurative otitis media. OME may occur during an upper respiratory infection, spontaneously because of poor eustachian tube function, or as an inflammatory response following AOM, most often between the ages of 6 months and 4 years. In the first year of life, .50% of children will experience OME, increasing to .60% by age 2 years. When children aged 5 to 6 years in primary school are screened for OME, about 1 in 8 are found to have fluid in one or both ears. The prevalence of OME in children with Down syndrome or cleft palate, however, is much higher, ranging from 60% to 85%.

Most episodes of OME resolve spontaneously within 3 months, but about 30% to 40% of children have repeated OME episodes, and 5% to 10% of episodes last year.⁶ Persistent middle ear fluid from OME results in decreased mobility of the tympanic membrane and serves as a barrier to sound conduction. At least 25% of OME episodes persist for  3 months and may be associated with hearing loss, balance (vestibular) problems, poor school performance, behavioral problems, ear discomfort, recurrent AOM, or reduced QOL. Less often, OME may cause structural damage to the tympanic membrane that requires surgical intervention.

The high prevalence of OME—along with many issues, including difficulties in diagnosis and assessing its duration, associated conductive hearing loss, the potential impact on child development, and significant practice variations in management makes OME an important condition for up-to-date clinical practice guidelines.