Otalgia is a general term that describes an earache or ear pain. The most common cause of otalgia in children is a middle ear infection, which is also called otitis media. Otitis externa, which affects the outer portion of the ear, and otitis interna, which affects the inner ear, are less common and have different symptoms than otitis media. In a middle ear infection, structures called the Eustachian tubes which drain fluid from the middle ear become blocked off, leading to fluid buildup behind the eardrum. This usually happens after a child has an upper respiratory infection, like a cold. This fluid puts increased pressure on the delicate membrane of the eardrum and causes an earache. The main symptoms of an ear infection are otalgia, hearing problems and a fever. If the fluid pressure behind the eardrum is too great, it may cause the eardrum to rupture. A ruptured eardrum is painful, but after it happens, the pressure and pain are usually decreased. The eardrum can heal itself in most cases.
Middle ear infections are extremely common in children, affecting about three quarters of children at some point, and some children suffer from chronic or recurring middle ear infections. Middle ear infections can also affect adults, but adults are far less susceptible to developing otitis media because their Eustachian tubes are a different size and shape and less prone to being blocked off and unable to drain fluid.
In adults, otalgia is far more likely to be caused by referred pain from other conditions than an ear infection. Referred pain is pain that comes from one area of the body and radiates to another area of the body. Some conditions that can cause earaches because of referred pain include sinus infections, arthritis that affects the temporomandibular joint (TMJ) of the jaw, temporomandibular joint syndrome, a tooth infection and a sore throat. In all of these cases, other symptoms besides otalgia are usually present that can help narrow down the diagnosis.
Another possibility for otalgia in both adults and children is acute trauma to the ear, including a perforated eardrum, foreign objects in the ear, an impaction of ear wax and damage to the ears caused by sudden changes in pressure. Otalgia is a symptom, not a disease, and any unexplained or severe earache pain should be checked out by a doctor.