Otoscopic Signs of Otitis Media

Background: Lack of agreed-upon diagnostic criteria for acute otitis media (AOM) has led to inconsistencies in clinical care, misleading research results, and misguided educational efforts. The objective of this study was to examine findings that expert otoscopists use when diagnosing AOM. Methods: A group of experienced otoscopists examined 783 children presenting for primary care. In addition, endoscopic still images of the tympanic membranes (TMs) were obtained. A random sample of 135 of these images was sent for review to a group of 7 independent physicians who were expert otoscopists. We examined the findings that both groups of observers used to distinguish between AOM, otitis media with effusion (OME), and no effusion. Results: Among both groups of observers, bulging of the TM was the finding judged best to differentiate AOM from OME: 96% of ears and 93% of ear image evaluations assigned a diagnosis of AOM by members of the 2 groups were reported as showing bulging of the TM, compared with 0% and 3%, respectively, of ears and ear image evaluations assigned a diagnosis of OME. Opacification of the TM was the finding that best differentiated OME from no effusion. Conclusions: We describe findings that are used by experienced otoscopists to diagnose AOM and OME. The findings point to the advisability under most circumstances of restricting antimicrobial treatment for AOM to children who have TM bulging, and they call into question clinical trials of the treatment of AOM in which TM bulging has not been a required element for participation.