Timing of egg introduction in infancy: does it really matter?

Published Online: September 21, 2016

The ideal age to introduce egg into an infant’s diet has been debated for the past two decades as egg allergy is one of the most common food allergies affecting young children. The Starting Time of Egg Protein (STEP) trial was designed to find out if egg allergy in infancy can be prevented by infants regularly eating egg from four to six months of age.  

In a recent article published in The Journal of Allergy and Clinical Immunology (JACI), Palmer and colleagues studied 820 infants without eczema at study entry but all infants had a family history of allergy (atopic mothers). Each infant in this STEP trial was randomly assigned to one of two groups. One group (egg introduction) of 407 infants were introduced to egg containing powder from 4-6 months of age which was mixed into their solid foods daily. The other group (egg avoidance) of 413 infants were introduced to a colour-matched rice based (egg-free) powder also from 4-6 months of age. All families were asked to follow an egg-free diet for their infant until 10 months of age.  Cooked egg was introduced to both groups of infants from 10 months of age when the study powder use was ceased. At 12 months of age, the infants had a medically observed pasteurized raw egg challenge to determine which infants had developed an egg allergy.

The authors found that feeding egg to infants between 4-6 and 10 months of age had no substantial effect on egg allergy in the first year. Overall, 7% of infants in the group that were given the egg powder developed an egg allergy by 12 months of age compared with 10% of the infants given the egg-free powder. Whether the infants were breastfeeding had no effect on the results. Likewise feeding egg from 4-6 months of age did not affect whether the infants became sensitised to peanuts or other allergens, developed eczema or had a wheeze.

In summary, for infants without eczema symptoms, regular egg eaten in solid foods from 4-6 months of age does not substantially alter the risk of egg allergy by 1 year of age.

The Journal of Allergy and Clinical Immunology (JACI) is an official scientific journal of the AAAAI, and is the most-cited journal in the field of allergy and clinical immunology.

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