Impacted cerumen: a disorder of keratinocyte separation in the superficial external ear canal?

In the majority of individuals, impaction of cerumen in the external auditory canal does not occur, and it is only a fraction of the population who regularly need to consult their physician for aural toilet. In this study we looked at the clinical features associated with recurrent cerumen impaction in 20 individuals. This was complemented by an examination of the cerumen plugs taken from their ears and hydrated to analyze the morphology of the keratin sheets, which had been observed in a previous study to constitute over one-half of the volume of impacted cerumen. In a further eight patients with cerumen, impaction plugs of cerumen were removed and subjected to histological examination. We observed that excessively long sheets of undivided keratin could be isolated from the hydrated cerumen plugs and that these sheets of keratin morphologically resembled the superficial layers of the stratum corneum of normal human deep external auditory canal skin. Based on these observations, we propose that cerumen impaction is the result of a failure in the normal keratinocyte separation which occurs in the superficial external auditory canal.