An unsuspected alkaline battery foreign body presenting as malignant otitis externa.

We describe a case of an unsuspected button battery foreign body in the ear canal causing symptoms that mimic malignant otitis externa in a previously healthy 13 year old. Button batteries in the ear canal may cause extensive liquefactive necrosis of the surrounding tissue by leaking an alkaline electrolyte solution. Suspicion of a foreign body should be maintained in any child presenting with a complicated otitis externa. Prompt evaluation and removal of button batteries are necessary to prevent tissue destruction.