Children given acetaminophen during the first year of life to reduce fever are more likely to develop asthma later on, a new study finds.

These children are also more likely to develop rhinoconjunctivitis and eczema when they reach age 6 to 7, according to the report in the Sept. 20 issue ofThe Lancet.

"If this association is causative, it would suggest that acetaminophen use is a risk factor for asthma and may explain the asthma has become more common," said lead researcher Dr. Richard Beasley, from the Medical Research Institute of New Zealand in Wellington.

Since this study can't definitively say that acetaminophen is a cause of asthma, its use for children shouldn't be changed, Beasley added. "Acetaminophen is the preferred drug for relief of pain and fever in childhood," he said.

Beasley thinks, however, acetaminophen should not be used routinely for childhood fever, but reserved for high fevers. "Acetaminophen is still the preferred agent, but the large amounts of acetaminophen used around the world are unnecessary," he said. "Its use should be limited to treat high fevers."

For the study, Beasley's group collected data on 205,487 children from 31 countries around the world. These children participated in the International Study of Asthma and Allergies in Childhood.

The researchers found that children who were given acetaminophen for fever during the first year of life had a 46 percent increased risk of developing asthma when they were 6 to 7 years old.

In addition, children who were given high doses of acetaminophen within the past year had a more than three times increased risk of asthma. Those who were given medium doses had a 61 percent increased risk of developing the condition, Beasley's team reported.

Acetaminophen use was also associated with an increased risk of severe asthma of about 22 percent to 38 percent, the researchers found.

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