Watch CBS News

Antibiotics before age 2 linked to allergies later

Taking antibiotics in early childhood may increase the odds for hay fever and the skin condition eczema later in life, a new study suggests.

Scientists from Utrecht University in the Netherlands presented their findings today at the European Respiratory Society International Congress in London. They combed through large medical databases looking for observational studies linking antibiotics taken from infancy to age 2 and the risk of eczema a red, itchy skin condition, and hay fever, also known as allergic rhinitis​. It’s caused by an allergic response to substances such as tree and ragweed pollen, dust mites, cats and dogs. All of the studies were published between 1966 and 2015.

They said that some previous research has connected early exposure to antibiotics with an increased risk of developing allergies later in life, but the results were inconsistent, so they hoped to find more answers.

Surprising health benefit of nail-biting? 01:18

They analyzed data from 44 studies including more than 650,000 patients with one or both conditions. They found that the risk of eczema increased between 15 and 41 percent in people who’d been exposed to antibiotics before the age of 2. The risk of hay fever in later life increased even more, with different studies showing it rose between 14 percent and 56 percent in those who’d taken antibiotics.

If a patient had been treated with two courses of antibiotics, the association was stronger for both conditions, the authors said in their abstract.

Dr. Carla Davis, director of the food allergy​ program at Texas Children’s Hospital in Houston, told CBS News that while an association between antibiotics and allergies is suggested by the study, questions still exist.

“We don’t know if the allergic disease caused increased amount of infections needing antibiotics, or if the antibiotics contributed to a change in the microbiome​ which may have influenced the development of allergic disease​. Both of these explanations are plausible. All we know is that early antibiotic use and allergies seem to go together,” said Davis.

Another difficulty with this study, she pointed out, is that it analyzed the use of many different kinds of studies -- case control, observational and cross sectional.

Dr. Jonathan Spergel, Chief of the Allergy Section and professor of pediatrics at the Perelman School of Medicine at the University of Pennsylvania, told CBS News many factors could be at play when it comes to early antibiotic use​ and the development of allergies later in life.

“Your microbiome, changes in where you live, what you eat, who your friends are and what your genetic background is,” he said.

The bottom line, Spergel said: “It’s important to give vaccines and immunizations​ when we can. Similarly, when you have a significant bacterial infection, you have to treat it. People die from meningitis and pneumonia. But you don’t want to give antibiotics when you have the common cold. Too many antibiotics definitely cause more diseases. Treat infections when they’re real infections and not when they’re not.”

View CBS News In
CBS News App Open
Chrome Safari Continue
Be the first to know
Get browser notifications for breaking news, live events, and exclusive reporting.