It's in the Genes: Some Kids Are Just More Susceptible to Ear Infections

Dec. 7, 1999 (Minneapolis) -- 'Tis the season. While parents are moaning ''Not another ear infection," scientists have been busy in the lab trying to find out why some kids are more likely to get them. Researchers at Children's Hospital of Pittsburgh have found a genetic component to inner ear infections in children, a component that can predispose some kids to the illness.

The good news for parents is that someday soon, physicians may be able to identify children who are at increased risk for ear infections and carry out preventive measures to eliminate the complications. The study is published in this week's issue of the Journal of the American Medical Association.

Inner ear infection -- also known as otitis media-- is inflammation or infection in the middle ear space. The illness typically occurs along with a cold (upper respiratory infection) and is responsible for more antibiotic administration and surgery than any other childhood affliction.

Otitis media occurs most often in the winter, during the cold and flu season. While most children have otitis media at least once before the age of 7 and usually respond to home treatment, untreated infections can result in hearing, developmental, and mental complications.

The researchers studied households with twins and triplets and found that there was a higher incidence of otitis media in identical siblings than in fraternal siblings. That rules out environmental factors as the sole cause of infection, since the twins and triplets had close contact with each other. Therefore, according to the researchers, a genetic component may be at work.

According to the author of the study, Margaretha L. Casselbrandt, MD, PhD, from Children's Hospital, finding a genetic link to ear infections can lead to possible prevention by avoiding risk factors. "Parents should try to eliminate risk factors such as bottle-feeding, daycare, and passive smoking," she tells WebMD. All three have been found to be aggravating factors for otitis media. "These children should be followed closely for the development of middle ear disease."

Garth D. Ehrlich, PhD, a genetic scientist at Allegheny General Hospital in Pittsburgh, says, "Otitis media is one of the most common pediatric diseases that has been firmly established as having a genetic component as well as environmental and infectious [makeup] ... [yet] physicians might not be accustomed to thinking about heredity in common illnesses such as otitis media." The findings may lead doctors to more closely observe siblings of ear infection-prone children.

Roland Eavey, MD, of Massachusetts Eye and Ear Infirmary in Boston, tells WebMD that the environmental component in ear infections -- that is, kids passing the infection on to others in day care -- is to be expected. But the hereditary factor is a bit more uncertain, he says.

"Because ear infections account for 25 million medical clinic visits a year, there is value in looking at this disorder," according to Eavey.

Eavey says that beyond families with twins, the study suggests that there can be tendencies within families for the same pattern of ear infections. One could imply that children should be checked more frequently for early signs of infection and more ambitiously treated with medications and ear tubes, he tells WebMD.

The study broadens the definition of what constitutes genetic disease, researchers say, and will compel scientists and physicians to look at infectious diseases in a new light.

Vital Information:

  • A new study shows that there may be a genetic component to inner ear infections that predisposes some children to the illness.
  • Inner ear infections are responsible for more antibiotic administration and surgery than any other childhood ailment.
  • If physicians could identify which children are at higher risk, preventive measures could be taken to avoid complications from the infection.