An ear infection, or otitis media, is the most common cause of earaches. Although this condition is a frequent cause of infant distress and is often associated with children, it can also affect adults. The infection in the middle ear (the space behind the eardrum where tiny bones pick up vibrations. 1 UMHS Otitis Media Guideline, April • Otitis media in adults • Care of otorrhea and acute otitis externa. * Adult: either mg BID x. Otitis media is inflammation of the middle ear; in the adult, is significantly MedicineNet does not provide medical advice.