Infections caused by bacteria or viruses trigger the body’s immune response, in which immune cells destroy the infectious agent. In the process, certain substances such as histamine are released from cells. These substances produce inflammation, which involves pain, swelling, redness and irritation of affected tissues. Unless the inflammation is treated, there is a risk that is can lead to long-term damage to tissues and structures in the ear, especially the blood vessels. The result is sensorineural hearing loss.
Patients may experience increasing trouble with hearing in one or both ears, usually developing slowly but sometimes occurring rapidly; dizziness; possibly facial paralysis. Some patients experience flu-like symptoms (fever, malaise, loss of appetite, fatigue). Rash, joint pain and other symptoms may develop depending on the nature of the underlying illness.