Otopathologic correlates of the continuum of otitis media.

It has been our hypothesis that different types of middle ear effusions and the clinical manifestations with which they are associated represent the typical inflammatory response. Employing an animal model under controlled conditions, we present statistical evidence that change in the mucosa of the middle ear in otitis media can occur along a continuum, with early forms regressing to more chronic stages of the disease. We also demonstrate an increase in the thickness and a decrease in the permeability of the round window membrane in a longitudinal study of otitis media in the same animal model. Histopathologic changes in human temporal bones with otitis media with effusion or chronic otitis media are similar to the changes in the animal models. These results support a concept that all categories of otitis media (serous, purulent, mucoid, and chronic) represent different stages in a continuum of events.