Middle ear and eustachian tube lining in chronic otitis media.

By means of histological observations we have tried to find morphological data on which to classify non-suppurative and suppurative chronic otitis media. There was also evidence of pathophysiological features which may have direct influence upon the development and behaviour of chronic inflammations of the tympanic cleft, such as disorders of ventilation and reaction of the mucoperiosteal layer. Local defence mechanisms, the species and virulence of infection also play an important role. It appears that the Eustachian tube is a very effective mechanical and immunological barrier against ascending infection which may perhaps be assisted by antibiotic treatment. Certainly non-suppurative chronic otitis media is more frequent now than in pre-antibiotic days.