Causes
The middle ear is connected to the throat by a small tube called the eustachian
tube. It's protected from the outside by a thin shield called a membrane.
Viruses and bacteria that normally live in the throat can sometimes cross into
the middle ear - through the eustachian tube - causing an infection.
Winter is high season for ear infections. They often follow a cold. Some
factors that increase a child's risk for middle ear infections include:
- crowded living or daycare conditions
- exposure to second-hand smoke
- respiratory illnesses
- close contact with siblings who have colds or ear infections
- having a cleft palate
- allergies that cause congestion on a chronic basis
Barometric trauma is another cause of ear infection. The pressure
in the middle ear rises when the airplane you are traveling on descends or
when you ascend while scuba diving. If the eustachian tube is not open, the
pressure in the middle ear cannot be equalized, and thus, may cause injury and
an acute ear infection.