An egg allergy is when the body responds abnormally to proteins found in egg whites or yolks. Symptoms of an allergic reaction can range from itchy hives to life-threatening anaphylaxis, although rare. As a result, those with egg allergy must be on constant guard about the ingredients in the products they consume and the products consumed around them. Many parents avoid exposing high-risk babies to eggs and other common food allergens for fear that early exposure may increase the chance of developing allergies.
Researchers wanted to determine whether regular consumption of egg protein from age 4 to 6 months reduces the risk of egg allergy in infants with hereditary risk. The study, published in The Journal of Allergy and Clinical Immunology, found that early oral raw egg exposure may not reduce the risk of egg allergy in infants without allergy symptoms or eczema.
About the study
The randomized controlled trial included 820 infants aged 4-6 months without allergy symptoms or eczema. All participants were at increased risk for hereditary allergies due to a maternal history of eczema. Participants were randomly assigned to 2 groups: 407 participants received pasteurized raw whole egg powder and 413 participants received rice powder (placebo) every day until age 10 months. Infants were followed until age 12 months.
At 12 months of age, participants were given pasteurized raw egg challenge and egg sensitization (skin prick) tests. In the intention-to-treat analysis (including infants with allergic reaction to the egg powder), egg allergy was found in 7% of the egg powder group vs. 10.3% of the rice powder group. In the per-protocol analysis (excluding infants with allergic reaction to the egg powder), egg allergy was found in 3% of the egg powder group vs. 9.9% of the rice powder group.
How Does this Affect You?
A randomized trial is considered the most reliable form of research, but how the research is done will affect its reliability. For example, this study has possible bias in that participants who ended the study due to allergic reaction to the egg powder were excluded from the per-protocol analysis.
Other studies have found that early introduction of egg protein may decrease the risk of egg allergy in children. However, one study included participants with multiple allergies , making the results applicable to a smaller proportion of the overall population. Previous studies also had other differences, such as starting egg at 3 months old rather than 4-6 months old as done in this study. These differences make it more difficult to identify subgroups that are likely to respond to the treatment.
Current guidelines state that there is insufficient evidence regarding when to introduce potentially allergenic foods. It remains to be seen whether guidelines will be updated as a result of this study. Talk to your doctor about your infant's nutrition. It is always important to be aware of negative reactions when introducing any new foods to your baby. If your infant is at risk for peanut allergy, talk to the doctor. A skin-prick test may help to determine whether your infant is allergic to peanuts. This information can help guide treatment and help you and the doctor discuss the best nutrition plan for your child.
RESOURCES
American Academy of Allergy, Asthma and Immunology http://www.aaaai.org
American Lung Association http://www.lungusa.org
References
Egg allergy. EBSCO DynaMed Plus website. Available at: http://www.dynamed.com/topics/dmp~AN~T921451/Egg-allergy
Palmer DJ, Sullivan TR, et al. Randomized controlled trial of early regular egg intake to prevent egg allergy. J Allergy Clin Immunol. 2017 May;139(5):1600-1607.
Revision Information
- Reviewer: EBSCO Medical Review Board Michael Woods, MD, FAAP
- Review Date: 12/2017