3 Ziemssen, ii. 112.
3. Tuberculosis is often associated with the catarrhal and purulent varieties of middle-ear inflammation, having, as a rule, a subacute course, the patient's attention sometimes only being drawn to his ear by the escape of pus from the middle ear into the external canal, the medium of communication being the mucous membrane of the pharynx viâ the Eustachian tube. Wendt4 states that as yet the presence of tubercles has not been authenticated, although the clinical observations of rapid destruction, especially of the tympanic membrane, would seem to indicate it.
4 Ibid., vii. 77.
4. Retro-nasal catarrh is a frequent cause of middle-ear inflammation, the disease being communicated along the mucous membrane of the Eustachian tube. All degrees of inflammation are found, the catarrhal variety being the most frequent, while acute nasal catarrh is a cause of a large number of ear complications. Chronic retro-nasal catarrh is apt to cause a chronic middle-ear catarrh, that progresses insidiously, and almost unnoticed by the patient until the deafness begins to interfere with the ordinary affairs of life.
5. Scrofulosis causes most frequently the catarrhal form of middle-ear inflammation; and this is a direct continuation of the catarrhal affections of the naso-pharyngeal mucous membrane viâ the Eustachian tube. Birch-Hirschfeld5 asserts that scrofulosis is the cause of the largest number of those cases in which weakening or destruction of the function of hearing has occurred during childhood; also, that the large number of scrofulous individuals found in deaf-and-dumb asylums is explained in this way; and that after the scrofulosis is cured the deafness remains as a result of permanent pathological middle-ear changes produced by the former disease.
5 Ibid., xvi. 794.
6. Smallpox may cause several varieties of middle-ear hyperæmia, and frequently also a hemorrhagic catarrhal process is met with. Not seldom is found a suppurative inflammation, with extensive destruction of the soft tissues and ossicles, with permanent subsequent deafness. There is probably no reason to doubt that a pustule itself can develop in the middle-ear mucous membrane, just as is found in the cornea, and cause an acute inflammatory process; but, as a rule, the middle-ear mucous membrane is secondarily involved as a consequence of inflammatory process existing in the naso-pharyngeal mucous membrane.
7. Diphtheria is a cause of middle-ear inflammation. Wendt6 states that in a fifth of the entire number of cases of croup and diphtheria; and in two-fifths of those cases in which the naso-pharyngeal space participated, but in no case without immediate connection with the corresponding affections of this space, he found an extension of the specific process into the middle ear. In some cases the tubal prominences were covered with membrane terminating at their orifices; in other cases a membranous cast of the cartilaginous portion of the tube was found. As a rule, the pathological changes noted were hyperæmia of the mucous membrane of the middle ear and catarrhal and purulent inflammation.
6 Ziemssen, vii. 71.