The effects of early and late paracetamol exposure on asthma and atopy: a birth cohort

Clin Exp Allergy. 2011 Mar;41(3):399-406. doi: 10.1111/j.1365-2222.2010.03610.x. Epub 2010 Sep 29.


Background: Despite reports of positive associations between paracetamol and asthma, the nature of these associations is unclear.

Objective: We aimed to investigate the associations between infant and childhood paracetamol use and atopy and allergic disease at 5-6 years.

Methods: In a birth cohort study, we collected reported paracetamol exposure between birth and 15 months in Christchurch (n=505) and between 5 and 6 years for all participants (Christchurch and Wellington) (n=914). Outcome data for reported current asthma, reported wheeze and atopy (measured using skin prick tests) were collected at 6 years for all participants. Logistic regression models were adjusted for potential confounders, including the number of chest infections and antibiotic use.

Results: Paracetamol exposure before the age of 15 months was associated with atopy at 6 years [adjusted odds ratio (OR)=3.61, 95% confidence interval (CI) 1.33-9.77]. Paracetamol exposure between 5 and 6 years showed dose-dependent associations with reported wheeze and current asthma but there was no association with atopy. Compared with use 0-2 times, the adjusted OR (95% CI) were wheeze 1.83 (1.04-3.23) for use 3-10 times, and 2.30 (1.28-4.16) for use >10 times: current asthma 1.63 (0.92-2.89) for use 3-10 times and 2.16 (1.19-3.92) for use >10 times: atopy 0.96 (0.59-1.56) for use 3-10 times, and 1.05 (0.62-1.77) for use >10 times.

Conclusion and clinical relevance: Our findings suggest that paracetamol has a role in the development of atopy, and the maintenance of asthma symptoms. Before recommendations for clinical practice can be made, randomized-controlled trials are needed to determine whether these associations are causal.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetaminophen / adverse effects*
  • Analgesics, Non-Narcotic / adverse effects*
  • Asthma / chemically induced
  • Asthma / epidemiology*
  • Child
  • Child, Preschool
  • Cohort Studies
  • Female
  • Humans
  • Hypersensitivity, Immediate / chemically induced
  • Hypersensitivity, Immediate / epidemiology*
  • Infant
  • Infant, Newborn
  • Male
  • Odds Ratio


  • Analgesics, Non-Narcotic
  • Acetaminophen