They are certainly the most common reason parents bring their kids to the doctor, but ear infections in young children are on the decline – and researchers think it might have to do with the fact that parents are smoking less.
In the past 15 years, visits to the pediatrician have declined nearly 30 percent for ear infections. Harvard researchers said because fewer adults are smoking, that’s less irritation to the child’s airways, and doctors are also using a vaccine against bacteria that cause ear infections. Breast-feeding is also an added protection.
“We’re sort of guessing here,” said Dr. Richard Rosenfeld, a New York-based ear, nose and throat specialist.
However, middle ear infections are still a problem for many American children, however, the Centers for Disease Control and Prevention has not reported on the issue in nearly two decades.
Cases skyrocketed from 1975-1990. The visit rate for children 5 and under more than doubled in that time.
A big reason, Rosenfeld said, was a steady rise in dual-career families. More families put their kids in day care, and day care is a breeding ground for the germs that lead to ear infections.
But the study by Harvard University suggests another contributor: cigarette smoke.
Most ear infections occur after a cold. In children, the ear is more directly connected to the back of the nose, so infections in a child's nose and throat can easily trigger ear inflammation. Such swelling is a fertile setting for the bacteria that cause ear infections.
Cigarette smoke, inhaled through a child's nose, can trigger the same kind of irritation and swelling, said Dr. Gordon Hughes of the National Institute on Deafness and Other Communication Disorders.
CDC figures show that 88 percent of U.S. nonsmokers were exposed to secondhand smoke around 1990, but that fell to about 40 percent in 2007 and 2008.
Harvard research indicates the decline coincides with a drop in childhood ear infections.
"When people are smoking less around their kids, when homes are smoke-free, the rate of ear infections can and has decreased," said Hillel Alpert, lead author of a study published recently by the journal Tobacco Control.
At the request of The Associated Press, the CDC checked its recent trend data on ear infections, based on annual surveys of a representative sample of doctors.
For children ages 6 and under, the number of medical visits in which the main diagnosis was ear infection dropped by nearly 30 percent from 1993 to 2008 — from an estimated 17.5 million visits to about 12.5 million.
The rate of such visits dropped by about 32 percent, from 636 ear infection-related visits per 1,000 children to 431 per 1,000.
The trend downward for very young children seems to have leveled off in the last few years.
A CDC analysis of data from 2004 through 2008 found the differences year-to-year were not meaningful, said Susan Schappert of the CDC's National Center for Health Statistics.
Some doctors have noticed fewer ear infections in their waiting rooms compared to what they saw years ago. "We don't see them that much anymore," said Dr. Michael Baron, a family practice doctor in Stone Mountain, a suburb of Atlanta.
Another factor in that decline may be growing use of a vaccine that protects against strep bacteria that can cause ear infections. The vaccine, first licensed in 2000, would not account for the drop in cases in the 1990s, but probably has contributed to the decline since, several experts said.
Also, some studies have credited antibody-rich breast milk with lowering infants' risk for respiratory and middle ear infections. About 77 percent of new mothers breast-feed, at least briefly, up from fewer than two-thirds in the early 1990s.
Of course, these are just theories.
The Associated Press contributed to this article.