Eustachian Tube Function and Allergy in Otitis Media

Abstract

Otitis media with effusion (OME) is one of the most common diseases of childhood. Acute OME is usually of the suppurative type, although it may be serous, while chronic OME has many synonyms, including "serous otitis media," "mucoid otitis," "nonsuppurative otitis media," "glue ear," and "allergic otitis media." The following discussion is a review of some of the factors that influence the etiology and pathogenesis of OME in general, and more specifically the role of Eustachian tube (ET) function and allergy in the disease process of OME. The pathogenesis of OME appears to be related to abnormal function of the ET. Investigation into the exact nature of this dysfunction requires an understanding of the system constituted by the palate, nasal cavity, nasopharynx, ET, middle ear, and mastoid air cells. Within this system the ET has at least three physiologic functions with respect to the middle ear: protection from nasopharyngeal sound pressure and secretions, clearance into the nasopharynx of secretions produced within the middle ear, and ventilation of the middle ear to equilibrate air pressure in the middle ear with atmospheric pressure and to replenish oxygen which has been absorbed (Fig. 1). ROENTGENOGRAPHIC STUDIES The protective and clearance functions of the ET have been assessed by a radiographic technique.1,2 Radiopaque material was instilled through the nose of patients in order to observe the retrograde flow of the medium from the nasopharynx into the ET. Patients were considered to have normal protective function when radiopaque material entered only the nasopharyngeal or isthmic portion of the tube but did not enter the bony portion of the tube or middle ear cavity.