A randomized trial of egg introduction from 4 months of age in infants at risk for egg allergy
Abstract
Epidemiological evidence suggests delayed introduction of egg may not protect against egg allergy in infants at risk of allergic disease.
Objective
To assess whether dietary introduction of egg between 4-6 months in infants at risk of allergy would reduce sensitization to egg.
Methods
We conducted a randomized controlled trial in infants with at least one first-degree relative with allergic disease. Infants with a skin prick test to egg white (EW-SPT) <2mm were randomized at age 4 months to receive whole-egg powder or placebo (rice powder) until 8-months of age, with all other dietary egg excluded. Diets were liberalized at 8-months in both groups. The primary outcome was EW-SPT ≥3mm at age 12-months.
Results
319 infants were randomized, 165 to egg and 154 to placebo. Fourteen infants reacted to egg within one week of introduction (despite EW-SPT <2mm at entry) and were unsuitable for intervention. 254 infants (83%) were assessed at 12 months of age. Loss to follow up was similar between groups. Sensitization to EW at 12 months was 20% and 11% in infants randomized to placebo and egg, respectively (OR=0.46, 95%CI 0.22-0.95, p=0.03, Chi-Square test). The absolute risk reduction was 9.8% (95%CI: 8.2% to 18.9%) with a number needed to treat of 11 (95%CI: 6 to 122). IgG4 to egg proteins and IgG4/IgE ratios were higher in those randomized to egg (p<0.0001 for each) at 12 months. There was no effect on the proportion of children with probable egg allergy (placebo 13, egg 8).
Conclusions
Introduction of whole-egg powder into the diets of high risk infants reduced sensitization to EW and induced egg-specific IgG4. However 8.5% of infants randomized to egg were not amenable to this primary prevention.
Reference
Wei-Liang Tan, John; Valerio, Carolina; Barnes, Elizabeth H et al. (2016) A randomized trial of egg introduction from 4 months of age in infants at risk for egg allergy. The Journal of Allergy and Clinical Immunology. http://www.jacionline.org/article/S0091-6749(16)31118-6/fulltext