A pediatric patient presents with upper respiratory symptoms. The student says there is acute otitis media. You look, and indeed there is some erythema of the tympanic membrane. But is this acute otitis media, and will the patient benefit from antibiotics?
Studies are limited by variable clinical definitions of acute otitis media (Chandler Clin Pediatr 2007) and interobserver variability (Margolis Is J Med Sci 1979). One article presents their training module as improving the accuracy of diagnosis by 5%, but that is only from 62% to 67%. The limitations in the diagnosis of acute otitis media are striking. (Kaleida Pediatrics 2009). Guidelines came out in 2005 but immediately received critical commentary (Hoover, Pellman Pediatrics 2005).
Using positive tympanocentesis culture as a gold standard, it becomes clear that bulging of the tympanic membrane is the most important indicator of bacterial acute otitis media (Schwatrz Clin Pediatr 1981). A yellow color was more common than red. In fact, in another study with culture as the gold standard, 15 patients had erythematous tympanic membranes as the only abnormality and not a single one grew bacteria on culture (Halsted Am J Dis Child 1968). This is not to say that color should be ignored, but to the beginner I would say this: Use the whole clinical context, and understand that distortion of anatomy is more important than color. If doubt remains, pneumatic otoscopy has some of the highest likelihood ratios of all the clinical signs.
TAKE HOME POINTS
-Bulging of the tympanic membrane is more predictive of culture-proven acute otitis media than erythema alone