Thorax doi:10.1136/thoraxjnl-2012-202150
  • Asthma
  • Original article

Multifaceted allergen avoidance during infancy reduces asthma during childhood with the effect persisting until age 18 years

  1. S Hasan Arshad1,2
  1. 1The David Hide Asthma and Allergy Research Centre, St Mary's Hospital, Newport, Isle of Wight, UK
  2. 2Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, UK
  1. Correspondence to Professor S Hasan Arshad, The David Hide Asthma and Allergy Research Centre, St Mary's Hospital, Newport, Isle of Wight PO30 5TG, UK; sha{at}
  1. Contributors SHA conceived the idea and worked with all the authors on the plan for recruitment, assessments and analysis, and reviewed and revised draft. MS undertook the recruitment and assessments, performed data entry and initial statistical analysis and wrote the first draft. AN reviewed and revised the statistical analysis. GR, SM and RK helped with the draft revisions. All the authors reviewed and discussed the results, contributed to the manuscript and approved the final version.

  • Received 11 May 2012
  • Accepted 6 July 2012
  • Published Online First 2 August 2012


Background Asthma is a chronic disease that often starts in childhood. The key risk factors are a child's environment and their genetic characteristics. The aim of this study was to evaluate the efficacy of environmental modification in the first 12 months of life on the prevalence of asthma in high-risk individuals.

Methods Children (n=120) considered at high risk of allergic disorders (either dual heredity or single heredity and a high cord total IgE), were enrolled in a single-blinded, randomised controlled trial. Infants in the intervention arm were either breast fed with the mother on a low allergen diet or given an extensively hydrolysed formula. Exposure to house dust mite allergen was reduced. The control group followed standard advice. Children were assessed at ages 1, 2, 4, 8 and 18 years for the presence of asthma and atopy.

Results At 18 years of age, there was a significantly lower prevalence of asthma in the prevention group compared with the control group (OR: 0.23, 95% CI 0.08 to 0.70, p=0.01), primarily due to asthma that developed during childhood but persisted until age 18 years. Repeated-measure analysis showed that there was an overall reduction in asthma prevalence from 1 to 18 years (OR: 0.51, CI 0.32 to 0.81, p=0.04). Prevalence of atopy was not significantly different between the two groups at age 18.

Conclusion Comprehensive allergen avoidance in the first year of life is effective in preventing asthma onset in individuals considered at high risk due to heredity. The effect occurs in the early years, but persists through to adulthood.


  • Funding Funding was provided by the National Institute for Health Research (Research for Patient Benefit) PB-PG-0906-11015.

  • Competing interests None.

  • Ethics approval Ethics approval was provided by NRES Committee South Central—Southampton B.

  • Provenance and peer review Not commissioned; externally peer reviewed.

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