Background: Exposure to paracetamol during intrauterine life, childhood, and adult life may increase the risk of developing asthma. We studied 67-year-old children from Phase Three of the International Study of Asthma and Allergies in Childhood (ISAAC) programme to investigate the association between paracetamol consumption and asthma.
Methods: As part of Phase Three of ISAAC, parents or guardians of children aged 67 years completed written questionnaires about symptoms of asthma, rhinoconjunctivitis, and eczema, and several risk factors, including the use of paracetamol for fever in the childs first year of life and the frequency of paracetamol use in the past 12 months. The primary outcome variable was the odds ratio (OR) of asthma symptoms in these children associated with the use of paracetamol for fever in the first year of life, as calculated by logistic regression.
Results: 205 487 children aged 67 years from 73 centres in 31 countries were included in the analysis. In the multivariate analyses, use of paracetamol for fever in the first year of life was associated with an increased risk of asthma symptoms when aged 67 years (OR 1·46 [95% CI 1·361·56]). Current use of paracetamol was associated with a dose-dependent increased risk of asthma symptoms (1·61 [1·461·77] and 3·23 [2·913·60] for medium and high use vs no use, respectively). Use of paracetamol was similarly associated with the risk of severe asthma symptoms, with population-attributable risks between 22% and 38%. Paracetamol use, both in the first year of life and in children aged 67 years, was also associated with an increased risk of symptoms of rhinoconjunctivitis and eczema.
Conclusions: Use of paracetamol in the first year of life and in later childhood, is associated with risk of asthma, rhinoconjunctivitis, and eczema at age 6 to 7 years. We suggest that exposure to paracetamol might be a risk factor for the development of asthma in childhood.
Lancet 2008; 372(9643): 1039-48.