Keratosis of the tympanic membrane and deep external auditory canal. A defect of auditory epithelial migration.

We have previously described the pathways of movement of epithelium on the tympanic membrane, showing that there are two discrete and separate zones. Four cases of keratosis of the tympanic membrane and deep external auditory canal are here reported. All patients complained of tinnitus and other aural symptoms. Sequences of otoscopic photography of daubs of dye placed on the tympanic membrane showed an abnormal anterior movement over the whole tympanic membrane in two cases and complete paralysis of movement in the two others. These findings suggest that the disorder arises from damage to basal epidermal cells caused by inflammation, which is probably due to infection. Treatment is by suction-stripping of keratin from the eardrum. Careful examination of the eardrum under magnification is required in all cases of tinnitus so as to detect this condition.