Current concepts of pathogenesis of otitis media: a review.

A number of important factors singly or in combination contribute to the pathogenesis of otitis media. These are poor tubal function, upper respiratory viral infection, bacterial adherence and nasopharyngeal flora, and immune status of the host. One of the important functions of the tubotympanum is to protect the middle ear from invading microbes. The host has available a number of strategies for this function including mucociliary protection, antibacterial secretory products, and specific immunodefenses. The microbes also possess the capability of escaping host defenses by enhancing their ability to adhere to mucosal surfaces, impairing mucociliary function and evading phagocytosis. Once microbes gain entrance to the middle ear, the microbes must overcome phagocytosis and immunodefense of the host, leading to otitis media. Recent data further indicate that specific qualitative and quantitative deficiencies in the immune system of children may predispose certain children to develop otitis media. These deficiencies appear to be in part due to a lack of maturity of the child's developing immune system as well as functional defects that are attributable to genetic or other unknown factors.