Ear Infections May Raise Kids' Asthma Risk

Study suggests a link, especially in children with recurrent ear trouble

TUESDAY, May 11, 2004 (HealthDayNews) -- Painful ear infections are tough on kids and their parents, and new research suggests they might also raise a child's risk for asthma.

"Higher rates of asthma were observed as the number of infections increased," said Kamal Eldeirawi, a researcher at the University of Illinois at Chicago's School of Public Health. "Children having three or more ear infections were approximately twice as likely to have asthma compared to those with no prior history of ear infections."

The findings appear in the May issue of Chest.

Pediatric experts estimate that 69 percent of American children will suffer an ear infection at some point in their early development, while a much smaller but still significant number of children -- about 5 percent -- will develop asthma.

Until recently, "there haven't been many studies that looked at asthma and ear infection," Eldeirawi said.

As part of their research, Eldeirawi and his team analyzed federal government health data collected between 1988 and 1994 on more than 7,500 children aged 2 to 11 years. Comparing rates of ear infection with any history of diagnosed asthma or wheezing, they found a significant association between early childhood ear infections and asthma.

Overall, children with any history of ear infection were at a 57 percent higher risk for asthma and a 70 percent elevated risk of non-asthmatic wheezing. Increasing recurrence of ear infection was associated with a steady rise in overall asthma risk, the researchers added.

Eldeirwai stressed, however, that the findings are preliminary and "long-term, follow-up studies" are needed before any recommendations can be made.

"Our findings aren't conclusive," he said. "They are only suggestive. Hopefully they will open up this avenue of research so people will start looking at it."

Dr. Stephen Wasserman, a professor of medicine at the University of California, San Diego, said he "wasn't particularly surprised" by the findings because experts have long noted a connection between ear infections and another common respiratory complaint, allergies.

Parents of ear infection-prone children need not become overly alarmed, he said, especially when it comes to links between ear trouble and wheezing. "Many kids wheeze in their early childhood from about age 1 through 3," Wasserman explained, "and they do not go on to wheeze later. It's now just called 'transient wheezing,' probably stemming from the fact that little kids' airways are just so small."

Still, the association between diagnosed asthma and ear infections remains puzzling. Eldeirawi said experts have already floated any number of theories to explain possible links between the two ailments.

"Studies have looked at repeated episodes of fever, which is a common symptom of ear infection, and found them to be related with asthma," he said. Other studies "have looked at the frequency of antibiotic use and the subsequent risk of having asthma, and they found a relationship there."

Viruses or bacteria that cause ear infection might also upset a child's immune system and encourage asthma, Eldeirawi said. Finally, a child's genetics might somehow predispose him or her to both ear infections and asthma, he added.

It may be years before scientists uncover the links -- if any -- between ear trouble and asthma. In the meantime, there's a lot parents can do to prevent their child from contracting either illness.

"For example, helping kids avoid tobacco smoke or avoiding environmental exposure to smoke," Eldeirawi advised, because secondhand smoke is strongly tied to both pediatric ear infection and respiratory illness. "Breast-feeding has also been found to reduce risk for ear infections, and in some studies it's even been found to reduce asthma," he said.

If children do develop an ear infection, Eldeirawi suggests avoiding unnecessary antibiotic therapy. "If their doctor prescribes antibiotics, [parents] should ask the doctor 'Is this really necessary? Will it go away without antibiotics?' Because a lot of ear infections will simply resolve without them."

More information

For tips on helping children through painful ear infections, visit the American Academy of Pediatrics. For more on pediatric asthma, check with the American Academy of Allergy, Asthma & Immunology.

SOURCES: Kamal Eldeirawi, M.S., graduate researcher, Division of Epidemiology and Biostatistics, School of Public Health, University of Illinois at Chicago; Stephen Wasserman, M.D., Ph.D., professor, medicine, University of California, San Diego; May 2004 Chest
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