An unusual case of otorrhoea due to parotid salivary fistula

Most salivary fistulae of the parotid gland open on to the skin surface and are a consequence of trauma to the main duct (Hemenway & Bergstrom, 1971) or to the gland itself (Joffe, 1967) or following surgical procedures. Despite the close proximity of the parotid gland to the external auditory meatus, post-surgical and traumatic fistulae into the external auditory meatus are extremely rare. Richards (1960) reported a case produced by an endaural incision for mastoid surgery. Even rarer is the formation of a spontaneous parotid salivary fistula into the external auditory meatus. A search of the English literature revealed only one previous report (Sharma & Dawkins, 1984) who postulated a patent foramen of Huschke and the repeated trauma of jaw movement on the parotid as the cause of the abnormal connection. However, investigation, including sialography, could not confirm this. We report a case of salivary fistula in which sialography was confirmatory, and both conventional and computed tomography (CT) of the external auditory meatus were helpful. A 58-year-old woman presented with a 9-month history of recurrent discharge from the right ear. Examination revealed typical otitis externa with accumulated squamous debris and red, oedematous canal skin. The tympanic membrane was seen to be intact. The left ear was normal. The condition settled with topical antibiotic drops but over the next 2 years she was seen repeatedly for further episodes of this unilateral otitis externa which settled each time with the same treatment.