otitis, Inflammation of the ear. Otitis externa is dermatitis, usually bacterial, of the auditory canal and sometimes the external ear. It can cause a foul discharge, pain, fever, and sporadic deafness. Otitis media is due to allergy or viral or bacterial infection of the middle ear. The bacterial form may be acute (causing earache, fever, and pus and requiring antibiotics) or chronic. It can invade the bone (mastoiditis), requiring surgery. Otitis in the inner ear (labyrinthitis) often arises from respiratory infection, syphilis, or otitis media. Symptoms include vertigo, vomiting, and hearing loss. Recovery is usually quick unless there is pus formation, which can destroy the inner-ear structures, causing permanent deafness in that ear.