Published online: October 11, 2016
The exponential rise in food allergy in the past 20 years has fuelled the search for practical primary prevention measures. The recent LEAP study demonstrated that the early introduction of peanut into an infant’s diet reduced the risk of peanut allergy. Egg is one of the most common food allergies worldwide and the most common in Australian children where the current study was conducted. Strict avoidance of egg in egg allergic children can be challenging for families, and may restrict their quality of life.
In the recently published study in The Journal of Allergy and Clinical Immunology (JACI), Tan and colleagues report on the results of a randomised control study which was designed to investigate whether introduction of dietary egg from 4 - 6 months of age would influence egg allergy skin tests at one year of age. Infants with a family history of allergy, but who were not positive on allergy skin tests to egg were included and randomly assigned to receive small amounts of daily egg (in a pasteurised powder) or a placebo (rice). The daily intervention was introduced as soon as successful introduction of the first weaning food had occurred. The infants otherwise avoided all egg in their diet until 8 months of age and were assessed at 12 months of age with allergy skin tests, food challenge and blood tests to assess immune markers of tolerance.
The authors found that infants who had received egg from 4-6 months of age had a 50% reduction in sensitization to egg on allergy skin tests when compared to infants receiving the placebo (rice) at 12 months. Infants taking egg also had significantly higher amounts of serum egg-specific immunoglobulins (IgG4), a pattern which is usually observed in individuals who become tolerant to allergens. The study did not find a significant reduction in the overall rate of egg allergy in the infants who received egg. Despite the fact that all infants had a negative skin test to egg at study entry, 8% of the infants randomised to receive egg reacted with mild/moderate allergic reactions to the egg within the first week of treatment and were unable to continue with the intervention. Infants with eczema at study entry were more likely to develop egg allergy but neither the severity nor prevalence of eczema at 8 or 12 months was associated with receiving egg treatment.
The author’s findings suggest that for infants at risk of allergic disease (based upon a family history) introduction of dietary egg may be beneficial for those infants who can tolerate its introduction. There were no serious egg allergic reactions experienced in this study.
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.