Ear infection is the most commonly diagnosed condition in children under 15, according to the National Institutes of Health. Almost half the children under the age of 1 have at least one bout of ear infections, and two-thirds of them experience one by the time they are 3. Understanding the causes of ear infections can help parents and other caregivers understand them better and possibly prevent some of them.
Colds
Infants and young children are susceptible to more colds and upper respiratory infections due to their immature immune system. Bacteria or viruses causing the cold can easily spread to the middle ear, where most ear infections occur. The ear infection, also called otitis media, is then characterized by swelling of the ear lining and buildup of fluid behind the eardrum.
Ear Structure
The structure of the inner ear changes slightly with age. The part of the ear most responsible for ear infections is the tube connecting the middle ear with the upper part of the throat, called the eustachian tube. In young children, the eustachian tube is narrower, shorter and more horizontal than in adults. This slight difference in structure puts young children, even healthy ones, at a higher risk for fluid buildup, because it doesn't drain as easily.
Allergies
A study conducted by Dr. Robert F. Labadie of the UNC-CH School of Medicine proposed that allergies increase the risk for ear infections in children. The fact that some children continue to have bouts of ear infections even after surgical placement of drainage tubes points to a possible link between ear infections and exposure to allergens. The inflammatory response to certain foods or environmental pollutants such as cigarette smoke causes swelling of the ear tissue and prevents normal drainage of ear fluid, thus creating the right environment for bacteria or viruses to multiply and cause an infection.
