The aetiology of otitis externa--a new concept.

This paper reports the results of middle ear pressure measurements on 33 patients with recurrent otitis externa and compares the results with those of 21 normal subjects. The maximum negative pressure in the control group was -50 mm. of water, while 17 patients (52%) with recurrent otitis externa recorded measurements of -100 mm. of water or more. It is postulated that chronic Eustachian tube dysfunction may interfere with the normal migration of epithelium from the tympanic membrane along the external auditory meatus leading to irritation and chronic infection. The treatment in these cases should be directed at the underlying cause of the Eustachian tube dysfunction.