O-20 - Early stepwise heated-egg introduction cut confirmed egg allergy at 12 months to 8% vs 38% placebo in eczema infants (PETIT RCT)
Primary outcome of the PETIT trial. Egg group received 50 mg/day heated egg powder from 6-9 months then 250 mg/day to 12 months. The trial was terminated early at a scheduled interim analysis of 100 participants (egg allergy 4/47 [9%] egg vs 18/47 [38%] placebo; RR 0.222 [0.081-0.607]; p=0.0012); interim stopping typically inflates the point estimate. Largest reported effect size among egg early-introduction trials.
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Randomised, double-blind, placebo-controlled trial (preregistered UMIN000008673) at two Japanese centres. 121 infants aged 4-5 months with eczema were randomised 1:1 (block size 4, stratified by institution and sex, allocation concealed, participants and physicians masked) to early egg introduction versus placebo. The egg group consumed 50 mg/day heated whole-egg powder from 6-9 months, then 250 mg/day until 12 months; both groups received aggressive eczema treatment maintained without exacerbation throughout. Primary outcome: proportion with hen’s-egg allergy confirmed by standardised, blinded open oral food challenge at 12 months, in all randomised participants who received the intervention. The trial was stopped early at a scheduled interim analysis of 100 participants.
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Why this is evidence
The core discriminating observation. A large, OFC-confirmed reduction (RR 0.221) in a double-blind, placebo-controlled RCT with identical aggressive eczema treatment in both arms is strongly predicted by H-10 (induced oral tolerance causally prevents allergy). H-46 (no causal effect; lower incidence is non-causal) can only accommodate the result through an artefact — differential dropout of already-reacting egg-arm infants — since randomisation and blinding rule out baseline selection and confounding; the observation therefore favours H-10 unless that specific dropout artefact is present.