Acetaminophen Use during infancy Not Linked to Eczema or Bronchiolitis Risk: Study

A new study published in the journal of The Lancet Child & Adolescent Health showed that by the time they were one year old, babies who took acetaminophen for pain or fever had no higher risk of developing bronchiolitis or eczema than those who took ibuprofen.

Early-life exposure to paracetamol has been linked in non-experimental research to a higher incidence of wheezing and eczema. Thus, this study examined the risk of eczema and bronchiolitis at one year of age using paracetamol and ibuprofen, as needed for fever or discomfort in the first year of life.

New Zealand-born infants under 8 weeks of age were randomly assigned (1:1) to receive either ibuprofen alone (5 mg/kg every 6 hours at age ≥3 months and 10 mg/kg every 6 hours at age ≥3 months) or paracetamol alone (15 mg/kg every 6 hours at age <1 months and every 4 hours at age ≥1 months) orally as needed for fever or pain until they were 1 year old. The New Zealand Formulary for Children served as the basis for dosage. Randomization was stratified by recruitment location, maternal asthma status, and multiple births using REDCap.

Key outcomes were hospitalization for bronchiolitis, defined as at least one hospitalization for bronchiolitis, viral-induced wheeze, or asthma in the first year of birth, and eczema as defined by the UK Diagnostic Criteria or hospitalization for eczema in the first year of life. The intention-to-treat premise guided the analysis.

3908 of the 3923 babies who were enrolled between April 2018 and July 2023 were included in the intention-to-treat analysis (1985 paracetamol, 1923 ibuprofen). In total, women made up 49.0%. There was no discernible difference in the incidence of eczema between the paracetamol group (16.2%) and the ibuprofen group (15.4%).

There was no discernible change in the prevalence of bronchiolitis, which was 4.9% against 4.3%, respectively. Serious side effects were uncommon, comparable across groups, and unrelated to the study drug. Overall, at one year of age, there was no indication that the risk of eczema or bronchiolitis differed significantly between paracetamol and ibuprofen.

Source:

Tan, E., McKinlay, C. J. D., Riley, J., Rao, M., Mravicich, L., Lawrence, S., Eathorne, A., Braithwaite, I., Semprini, A., Okesene-Gafa, K., Sheridan, N., Hoare, K., Grant, C., Johnson, D., Weatherall, M., Beasley, R., & Dalziel, S. R. (2026). Paracetamol versus ibuprofen as required for fever or pain in the first year of life and the risk of eczema and bronchiolitis at age 1 year in New Zealand (PIPPA Tamariki): a multicentre, open-label, parallel-group, superiority, randomised controlled trial. The Lancet. Child & Adolescent Health. https://doi.org/10.1016/S2352-4642(25)00341-4