Plain language summary
The egg allergy is a common allergy mediated by IgE antibodies. Randomised, double-blind, single-site, parallel-arm, controlled study investigated whether early egg introduction could help to prevent or reduce the risk of developing egg allergy. Three hundred and nineteen infants of four months of age with atopic diseases were randomised to receive either 350 mg of freeze-dried egg protein (pasteurized whole egg powder) or rice powder as a placebo daily for four months of intervention. At twelve months, sensitisation to egg white was lower in infants who were randomised to egg (11%) than the infants who were randomised to receive rice powder (20%). The high-risk infants who received the egg white showed significant induction of egg specific IgG4 antibody levels and two major egg protein components such as ovalbumin and ovomucoid at the age of twelve months. There is a need for further robust research using a generalised population in order to confirm the generalisability of the results of this study. Healthcare professionals can use the findings of this study to plan infant weaning strategies.
Abstract
BACKGROUND Epidemiologic evidence suggests delayed introduction of egg might not protect against egg allergy in infants at risk of allergic disease. OBJECTIVE We sought to assess whether dietary introduction of egg between 4 and 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 1 first-degree relative with allergic disease. Infants with a skin prick test (SPT) response to egg white (EW) of less than 2 mm 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 an EW SPT response of 3 mm or greater at age 12 months. RESULTS Three hundred nineteen infants were randomized: 165 to egg and 154 to placebo. Fourteen infants reacted to egg within 1 week of introduction (despite an EW SPT response <2 mm at entry) and were unsuitable for intervention. Two hundred fifty-four (83%) infants 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 (odds ratio, 0.46; 95% CI, 0.22-0.95; P = .03, χ2 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, 6-122). Levels of IgG4 to egg proteins and IgG4/IgE ratios were higher in those randomized to egg (P < .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 levels. However, 8.5% of infants randomized to egg were not amenable to this primary prevention.
Methodological quality
Jadad score
:
5
Allocation concealment
:
Yes
