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    Infants and Antibiotics: Asthma Risk?

    Research Suggests Link Between Antibiotic Use by Infants and Development of Asthma

    More Findings

    Within the group, 6% of the children had asthma by age 7. Antibiotic use was widespread, with 65% of the children having been prescribed at least one course of the medication during the first year of life.

    The researchers found that for children who got the medications for nonrespiratory infections, the risk of getting asthma by age 7 was nearly twice as likely as children who got no antibiotics from birth to age 1 year.

    The finding strengthens the idea that early antibiotic use and asthma are linked, Kozyrskyj says. "In that case you can't say maybe [the asthma] was due to the respiratory tract infection."

    If the household of children taking multiple medication courses did not have a dog, the children's risk of getting asthma doubled, she found. "Dogs bring in different germs," she says. And that could strengthen a child's immunity.

    In the study, cats didn't offer the same effect, she says, and may actually boost risk, although the evidence for that in the study was weak.

    Explaining the Link

    Exactly why the early antibiotic use may boost asthma risk later isn't certain, Kozyrskyj says. She speculates that because antibiotics can kill off the microflora (natural bacteria) in your intestinal tract, "it may change your immune system, making you more vulnerable to developing asthma."

    Still, she emphasizes, asthma is a complex disease. "It's also genetic. We've identified one factor." But many factors underlie the condition, she says.

    Second Opinion

    One strength of the study, according to an allergist not involved in it, is that the researchers found the link held up between antibiotics and asthma not just for the children who were treated for respiratory infections.

    "The researchers make the argument that these kids [treated for nonrespiratory infections] were not destined for asthma" yet developed it after the antibiotic treatment, says William Anderson, MD, a board-certified allergist in Bellingham, Wash.

    Advice for Parents

    When your child has an infection and your child's doctor suggests an antibiotic, what’s best? "A parent might question the need for an antibiotic," Anderson says, and ask about other options. But, he emphasizes, "there are cases when a kid really needs an antibiotic."

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