Paracetamol Use in Infancy and Risk of Asthma in Children Aged 6 to 7 Years:
Presented at ERS
BERLIN -- October 8, 2008 -- The reported use of paracetamol (acetaminophen) in the first year of life is associated with increases in reported symptoms of asthma and risk of severe asthma symptoms in children aged 6 to 7 years, according to analysis of data from the multicentre, multicountry, cross-sectional International Study of Asthma and Allergies in Children (ISAAC).
The study also found an association between use of paracetamol in childhood and an increased risk of symptoms of rhinoconjunctivitis and eczema in childhood, said principal investigator Richard Beasley, MD, Medical Research Institute of New Zealand, Wellington, New Zealand.
The increased international use of paracetamol over the last 40 years occurred contemporaneously with an increased prevalence of asthma, Dr. Beasley said during a presentation on October 7 at the European Respiratory Society (ERS) 18th Annual Congress.
"[This study] was based on a hypothesis that was raised 10 years ago, where it was proposed that the switch from aspirin to paracetamol in childhood may have contributed to the increase in asthma prevalence that was noted in many countries in the 1980s," he said.
Therefore, Dr. Beasley and colleagues conducted a study to investigate the association between paracetamol use in infancy and self-reported symptoms of asthma in children aged 6 to 7 years participating in the ISAAC program, which was formed in 1991 to facilitate research into asthma, allergic rhinitis
Data were obtained from 2 groups (children aged 6 to 7 and 13 to 14) from random samples of schools in defined geographical areas worldwide. Samples were collected using 2 simple standardised questionnaires that were completed by the children's parents or guardians.
The prevalence questionnaire obtained data regarding symptoms of asthma, rhinoconjunctivitis, and eczema in these children, while the environmental questionnaire obtained data on a wide range of putative protective and risk factors for asthma and allergic disorders, including paracetamol use for fever in the first year of life.
A total of 194,555 children from 69 centres in 29 countries were included in the analysis, with the multivariate analysis based on 105,041 of these children with complete covariance data.
This multivariate analysis of the associations with paracetamol use showed significant odds ratios (ORs) as follows: asthma, 1.46 (95% confidence interval [CI], 1.36-1.56); rhinoconjunctivitis, 1.48 (95% CI, 1.38-1.60); and eczema, 1.35 (95% CI, 1.26-1.45).
When severe asthma symptoms were defined as wheezing causing sleep disturbance or limiting speech, or 4 or more attacks of wheezing in the past 12 months, a similar significant association was seen at the multivariate level for the use of paracetamol (OR, 1.43; 95% CI, 1.30-1.58).
Dr. Beasley noted, "While paracetamol has been shown to be safer than the alternatives and is the recommended treatment ... what we found in this study was that there was a very widespread use of paracetamol beyond its indication for relief of high fever."
Indeed, as he stressed, "What we need now is randomised controlled trials to really sort this out properly, and from these trials, there will be the basis for making firm guidelines in terms of management."
The study was published in The Lancet in September 2008 (Beasley R et al. 2008;372:1039-1048).