Early food intervention and skin emollients to prevent preschool asthma

Abstract

<b>Background:</b> Research suggests that atopic dermatitis and allergic sensitisation are major risk factors for asthma development. <b>Objective:</b> The objective was to explore if primary prevention by skin emollients and early allergenic food introduction reduced the risk of asthma in preschool children. <b>Methods:</b> In PreventADALL, 2397 infants from the general population in Norway and Sweden were randomized at birth to either no intervention, skin intervention (regular skin emollients from 2-32 weeks of age), food intervention (exposure to peanut, cow’s milk, wheat, and egg from 3 months of age) or both interventions. Asthma was defined as fulfilling at least 2 of 3 criteria; 1) ≥3 episodes of bronchial obstruction, 2) doctor diagnosis of asthma, and 3) use of asthma medication after 9 months of age, all reported in questionnaires every 3-6 months from 3-36 months of age. The primary outcome was asthma by 3 years of age by intention-to-treat (ITT), with missing outcome handled by multiple imputation with chained equations. (clincialtrials.gov NCT02449850) <b>Results:</b> The overall prevalence of asthma by 3 years was 13.2%; 69/488 (14.1%) in the no-intervention group, 53/418 (12.7%) with skin intervention, 70/510 (13.7%) with food intervention, and 53/437 (12.1%) with both interventions, using complete case data. The risk of asthma was not significantly affected by the interventions, with an ITT main effect risk difference of 2.7% (95% CI -1.3 to 6.8) and -0.5% (95% CI -5.2 to 4.3) by skin and food intervention respectively. No significant interaction effect (p=0.63) was observed. <b>Conclusion:</b> Primary prevention strategies aimed at reducing atopic dermatitis and/or food allergy, did not reduce the risk of asthma by 3 years of age.