Optimum management of the discharging ear.

Abstract

Discharge from the ear can be the result of many disease processes. The ear may discharge blood, pus, cerebrospinal fluid (CSF) or wax. Keratosis obturans, stenosis of the external meatus and benign tumours of the external meatus all lead to wax build-up, which may cause recurrent attacks of otitis externa. Malignant tumours, such as basal cell carcinoma, squamous cell carcinoma and tumours of ceruminous gland origin may also present with discharge. Tumours should be excluded by submitting all material removed from the external canal for histological examination. Single or multiple abscesses (known as furuncles) may occur in the hair follicles in the skin of the external acoustic meatus (EAM). Compulsive scratching, hearing aids and foreign bodies placed in the ear predispose to otitis externa, which is also often associated with infection by Pseudomonas aeruginosa, Staphylococcus aureus and faecal organisms. Management may be with aluminium acetate 14%, topical antibiotic/steroid drops, a gauze wick soaked with icthammol 10% in glycerin or polymyxin B sulphate--neomycin sulphate--hydrocortisone acetate cream placed into the EAM and replaced every 24 to 48 hours, or systemic antibiotics according to severity. Malignant (necrotising) otitis externa causes progressive destruction of the temporal bone, and cranial nerve palsies (usually facial first). Treatment is limited debridement of infected bone, accompanied by intravenous aminoglycosides, and local antibiotic treatment and aural cleanout or oral ciprofloxacin. Middle ear conditions causing discharge include acute otitis media, infected grommets, traumatic perforations and chronic suppurative otitis media, as well as tumours of the ear canal skin and middle ear, radiation-induced otitis externa and osteoradionecrosis of the temporal bone, tuberculosis, Langerhans cell histiocytosis, spontaneous or post-traumatic CSF leaks, Wegeners granulomatosis and immune deficiency states. Topical application of aminoglycoside antibiotics to the middle ear of laboratory animals such as rats, guinea pigs and chinchillas causes sensorineural hearing loss, an effect rarely seen clinically in humans. If the external acoustic meatus and tympanic membrane are obscured by discharge cotton buds, microsuction equipment or syringing are used to remove it. It is often useful to initiate treatment (usually with topical drops, wicks or an oral antibiotic) with a provisional diagnosis. A full examination and adequate visualisation of the tympanic membrane must eventually be performed, if necessary under anaesthesia, or else serious progressive conditions may be neglected. The most useful initial investigation is a swab sent for bacteriological assessment; other investigations are usually indicated by clinical findings and the provisional diagnosis.