More than twenty recent studies found an increased risk of asthma among children that had taken acetaminophen, the main ingredient in Tylenol.
Researchers believe the drug can reduce the level of a peptide that repairs the damage caused by inflammation.
Doctors say it's still too early to say that kids should completely avoid acetaminophen.
For the moment, they suggest that parents use the drug sparingly, using it only for high fevers or for major pain relief.
