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Understanding Ear Infection - the Basics
What Is an Ear Infection?
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 (where tiny bones pick up vibrations from the eardrum and pass them along to the inner ear) very often accompanies a common cold, the flu, or another type of respiratory infection. This is because the middle ear is connected to the upper respiratory tract by a tiny channel known as a eustachian tube.
Most parents are frustratingly familiar with ear infections. Except for wellness baby visits, ear infections are the most common reason for trips to the pediatrician, accounting for approximately 30 million doctor visits a year in the U.S. Today, almost half of all antibiotic prescriptions written for children are for ear infections, and the cost of treating middle ear infections in the U.S. has been estimated at $2 billion a year. Untreated, ear infections can lead to more serious complications, including mastoiditis (a rare inflammation of a bone adjacent to the ear), hearing loss, perforation of the eardrum, meningitis, facial nerve paralysis, and possibly Meniere's disease.
What Causes an Ear Infection?
Cells in the middle ear make a fluid that, among other things, help keep out invading organisms. Normally, the fluid drains out through the eustachian tube and into the throat. But if the eustachian tube becomes swollen or blocked the fluid can become trapped in the middle ear, forming a breeding ground for bacteria and viruses that can cause the area to become inflamed and infected. This tube lies in a more horizontal position and is shorter in children, which may put them at even greater risk of infection. To the doctor, the eardrum of an infected patient appears red and bulging.
The most common cause of an ear infection is an upper respiratory viral infection, such as a cold or the flu. These disorders can make the eustachian tube so swollen that middle ear fluid cannot drain. Allergies -- to pollen, dust, animal dander, or food -- can produce the same effect as a cold or flu, as can smoke, fumes, and other environmental toxins. Bacteria can cause an ear infection directly, but usually these organisms come on the heels of a viral infection or an allergic reaction, quickly finding their way into the warm, moist environment of the middle ear. Invading bacteria can wreak major havoc, turning inflammation into infection and provoking fevers. Among the bacteria most often found in infected middle ears are the same varieties responsible for many cases of sinusitis, pneumonia, and other respiratory infections. (Note: Flu shots do not offer protection from ear infections.)
WebMD Medical Reference
