Ear Infections - Risk Factors

Risk Factors

Acute ear infections account for 15 - 30 million visits to the doctor each year in the U.S. In fact, ear infections are the most common reason why an American child sees the doctor.

Age

Acute Otitis Media (AOM). About two-thirds of children will have a least one attack of AOM by age 3, and a third of these children will have at least three episodes. Boys are more likely to have infections than girls.

AOM generally affects children ages 6 - 18 months. The earlier a child has a first ear infection, the more susceptible they are to recurrent episodes (for instance, three or more episodes within a 6-month period).

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As children grow, the structures in their ears enlarge and their immune systems become stronger. By 16 months, the risk for recurrent infections rapidly decreases. After age 5, most children have outgrown their susceptibility to any ear infections.

Otitis Media with Effusion. OME is very common in children age 6 months to 4 years, with about 90% of children having OME at some point. More than 50% of children have OME before the age of 1, and more than 60% by age 2.

Other Risk Factors

Ear infections are more likely to occur in the fall and winter. The following conditions also put children at higher risk for ear infection:

• Allergies. Some doctors believe that an increase in allergies is also partially responsible for the higher number of ear infection cases. Allergies can cause inflammation in the airways, which may contribute to ear infections. Allergies are also associated with asthma and sinusitis. However, a causal relationship between allergies and ear infections has not been definitively established.
• Enrollment in day care. Although ear infections themselves are not contagious, the respiratory infections that often precede them can pose a risk for children who have close and frequent exposure to other children. Some research suggests that the increasing rate of ear and other infections may be due to the increasing attendance of very small children, including infants, in day care centers.
• Exposure to second-hand cigarette smoke. Parents who smoke pose a significant risk that their children will get both otitis media with effusion (OME) and recurrent acute otitis media (AOM). (Passive smoking does not appear to be a cause of initial ear infections, however.)
• Being bottle-fed as infants. Babies who are bottle-fed may have a higher risk for otitis media than breastfed babies. The American Academy of Pediatrics recommends breastfeeding for at least the baby's first 6 months.
• Pacifier use. The use of pacifiers may place children at higher risk for ear infections. Sucking increases production of saliva, which helps bacteria travel up the Eustachian tubes to the middle ear.
• Obesity. Obesity has been associated with risk for OME.
• Having siblings with recurrent ear infections.

Review Date: 05/03/2011
Reviewed By: Harvey Simon, MD, Editor-in-Chief, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org).