Comparison of the Pathologic Findings among Various Experimental Otitis Media with Effusion

Abstract

Otitis media with effusion (OME) was induced in chinchillas by various procedures and pathologic findings of these animals were observed to elucidate the pathogenesis of this disorder. Obstruction of the pharyngeal orifice, and inoculation of endotoxin or middle ear effusion into the tympanic cavity were the procedures of the induction of OME. Cytologic and biochemical findings (histamine and PGE₂concentrations) of the effusion, and histopathology of the middle ear mucosa of these OME-induced chinchillas were compared with those of immune-mediated OME. Although there was a variety of degree of these changes, no significant difference was seen among OMEs induced by different procedures. OME is perhaps a multifactorial disease. Findings of this study suggest the difficulty in knowing the cause by the pathologic feature of tympanic cavity.