Foreign bodies are commonly found in the external auditory canal (EAC) of children and sometimes in adults.1 Children commonly place small objects such as food (e.g., beans, peas, corn, and seeds) or small round objects (e.g., beads, rocks, and toys) in the EAC.2–5 Adults are more likely to suffer from items used to clean or scratch the ear (e.g., cotton swab, paper, paper clips, and pencil lead) and insects that crawl into the ear.4 The EAC and tympanic membrane (TM) are exquisitely sensitive and delicate.3,6 Foreign bodies in the EAC are extremely irritating to patients; especially live insects that will scratch the TM in an effort to escape. Injuries can occur unless proper care is taken in the removal of EAC foreign bodies.
The EAC is S-shaped and 2.5 cm long in adults.7 The lateral or distal third is cartilaginous, with thick skin. It has more hair follicles, glands, and subcutaneous tissue than the medial or proximal two-thirds of the EAC. The medial EAC is bony, with a thinner and more fragile layer of skin.7,8 The narrowed isthmus is located between the cartilaginous and bony portions.2,7 The canal ends medially at the TM, which is situated obliquely to increase the surface area for carrying sound energy to the middle ear.8 The anteroinferior EAC is 0.6 mm longer than the posterosuperior portion.7 Auriculotemporal branches of cranial nerves V, VII, IX, and X and the greater auricular nerve of the cervical plexus supply sensation to the EAC.7
All EAC foreign bodies must be removed. The only question is how quickly this must be done, who should do it, and which is the safest of available techniques. The method used is individualized to the patient, type of foreign body, Emergency Physician preference and experience, and the availability of an Otolaryngologist. Some foreign bodies are very easily and safely removed with the equipment available in any Emergency Department. Others—due to impaction, large size, sharp edges, location in the canal, involvement of the TM or middle ear structures, or patient age—will require removal under general anesthesia or even an approach to removal from outside the canal.2,6,9
The most urgent indication for immediate removal is an alkaline button battery because of the extensive and severe damage it may cause in a very short time.1 These are most commonly found in the EAC of a young child. There are two mechanisms for the rapid destruction of surrounding tissues by the batteries. The moisture and cerumen in the EAC have a high conductivity, which causes conduction of electric current from the battery and results in localized electrical burns. Local inflammation from those burns will cause fluid exudation into the EAC. This increases the electrical conduction injury and causes the battery to begin leaking alkaline electrolyte solution, which can penetrate deeply into underlying ...