Traumatic laceration of the external auditory canal may result in the implantation of keratin squames and bacteria into the dermis and the subsequent development of an acute otitis externa. The implanted keratin squames incite a foreignbody type of granulomatous reaction and produce a friable exuberant polyp arising from the skin of the external canal in the region of the original laceration.
Histologically, the polyp is characterized by the presence of oval slit-like spaces containing keratin squames and surrounded by foreign body giant cells.