Nearly 4,000 babies in New Zealand were enrolled in a landmark clinical trial to answer a question that has troubled parents and doctors for years: do common infant pain relievers cause eczema or other health problems?
The answer, according to a study published in The Lancet Child and Adolescent Health, is no. Researchers at the University of Auckland found no evidence that either acetaminophen, sold as Tylenol or paracetamol, or ibuprofen, sold as Advil, increases the risk of eczema or bronchiolitis during a baby's first year of life.
The study was the first randomized controlled trial, considered the gold standard in medical research, to directly examine this question. Earlier observational studies had raised concerns that acetaminophen given in infancy might be connected to eczema, asthma, or other childhood conditions. Those studies had made some parents hesitant to use medicines that doctors commonly recommend for fever and pain relief.
In the trial, babies were randomly assigned at birth to receive either acetaminophen or ibuprofen whenever medication was needed during their first year of life. Parents were regularly asked whether their children had developed eczema, asthma symptoms, or bronchiolitis. Researchers also reviewed prescription records and hospital data.
The results were close across both groups. About 16 percent of babies in the acetaminophen group developed eczema, compared with 15 percent in the ibuprofen group. Bronchiolitis affected roughly five percent of children in each group. Researchers found these differences were not statistically significant. No serious side effects were attributed to either drug.
Lead researcher Professor Stuart Dalziel, Cure Kids Chair of Child Health Research at Waipapa Taumata Rau, University of Auckland, and a pediatrician at Starship Children's Hospital, described the findings in direct terms. "Our study found that paracetamol and ibuprofen are incredibly safe to use in young children," Dalziel said.
He noted that both medicines rank among the most commonly prescribed or purchased over-the-counter drugs for babies worldwide. "These results give parents and health professionals high confidence to continue to use these important medications," he said.
Researchers noted that acetaminophen and ibuprofen are among the most widely used medicines in pediatric care globally. The reassurance this study provides is relevant to millions of families who rely on these drugs to manage pain and fever during a child's earliest months.
The study is not finished. Researchers plan to continue following the children through age six to look for any possible long-term effects. That follow-up data will be critical for understanding whether the safety findings from the first year hold up as the children grow older and their immune systems develop further.
