How does one tell if an ear infection is viral or bacterial?

Sometimes difficult: Your doctor has to gauge according to the history you provide, what the ear drum looks like, and whether the eardrum moves or not. If there's no fever, mild or no pain, the ear drum moves, and the patient has cold symptoms it's usually viral and antibiotics are inappropriate. If there's fever, pain, lack of movement of a very red eardrum, it's likely bacterial.