Ear infections, also known as acute otitis media, are caused by a bacterium or virus in the middle ear. These infections often result from another illness such as a cold, flu, or allergy that causes congestion and swelling of the nasal passages, throat, and eustachian tubes. The eustachian tubes are a pair of narrow tubes that run from each middle ear to high in the back of the throat, behind the nasal passages. The throat end of the tubes open and close to regulate air pressure in the middle ear.

Risk factors for ear infections include:

• Age: Children are more likely than adults to get ear infections because their eustachian tubes are shorter and more horizontal than those of adults, making it easier for germs to travel from the nose and throat to the middle ear.
• Seasonal factors: Ear infections are most common during the fall and winter.
• Infant feeding: Babies who drink from a bottle, especially while lying down, tend to have more ear infections than do babies who are breast-fed.
• Exposure to people with colds: Ear infections can be contagious, so exposure to people with colds can increase the risk of getting an ear infection.
• Allergies: 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.

Symptoms of an ear infection often begin after a cold and include ear pain, fever, fussiness or irritability, rubbing or tugging at an ear, and difficulty sleeping. Treatment may begin with managing pain and monitoring the problem, but antibiotics are sometimes used to clear the infection. It is important to see a doctor if a child has a fever of...