Is there a march from early food sensitization to later childhood allergic airway disease? Results from two prospective birth cohort studies

Background: The march from early aeroallergen sensitization to subsequent respiratory allergy is well established, but it is unclear whether early life food sensitization precedes and further increases risk of allergic airway disease. Objective: To assess the association between food sensitization in the first 2 years of life and subsequent asthma and allergic rhinitis by age 10-12 years. Methods: We used data from two independent cohorts: the high-risk Melbourne Atopic Cohort Study (MACS) (n = 620) and the population-based LISAplus (n = 3094). Food sensitization was assessed at 6, 12, and 24 months in MACS and 24 months in LISAplus. Multiple logistic regressions were used to estimate associations between sensitization to food only, aeroallergen only, or both and allergic airway disease. Results: When compared to non-sensitized children, sensitization to food only at 12 months in MACS and 24 months in LISAplus was associated with increased risk of current asthma (aOR = 2.2; 95% CI 1.1, 4.6 in MACS and aOR = 4.9; 2.4, 10.1 in LISAplus). Similar results were seen for allergic rhinitis. Additionally, cosensitization to food and aeroallergen in both cohorts at any tested point was a stronger predictor of asthma (at 24 months, aOR = 8.3; 3.7, 18.8 in MACS and aOR = 14.4; 5.0, 41.6 in LISAplus) and allergic rhinitis (at 24 months, aOR = 3.9; 1.9, 8.1 in MACS and aOR = 7.6; 3.0, 19.6 in LISAplus). Conclusions: In both cohorts, food sensitization (with or without aeroallergen sensitization) in the first two years of life increased the risk of subsequent asthma and allergic rhinitis. These findings support the role of early life food sensitization in the atopic march and suggest trials to prevent early onset have the potential to reduce the development of allergic airways disease.