5MinuteConsult Journal Club
Peanut & Egg Food Allergies Reduce by Age 6 Years
J Allergy Clin Immunol; 2022; https://doi.org/10.1016/j.jaci.2022.04.008
Observational cohort study of 5276 children recruited at age 1 year and have been followed prospectively to determine the natural history of peanut and egg allergies. Children were skin prick tested yearly starting at 12 months for 4 common food allergens: peanut, egg, sesame, and either cow’s milk or shellfish. Those who developed a wheal underwent oral food challenges. These children were then tested every year going forward.
For Peanut Allergy: 3% of those tested at 1 year were positive for peanut allergy. By 6 years. 29% of those children had resolved their allergy. Factors of children with persistent allergies included early-onset severe eczema (adjusted OR = 3.23; 95% CI, 1.17-8.88), sensitization to at least one tree nut (aOR = 2.51; 95% CI, 1-6.35) and a positive skin prick test (OR = 2.35; 95% CI, 1.08-5.12) at 1 year.
For Egg Allergy: 9% of those tested at 1 year were positive for egg allergy. By 6 years, 89% of those children had resolved their allergy. Persistent egg allergy was more likely with early-onset severe eczema (aOR = 3.77; 95% CI, 1.35-10.52), peanut or sesame food sensitizations (aOR = 2.8; 95% CI, 1.11-7.03), baked egg allergy (aOR = 7.41; 95% CI, 2.16-25.3) at 1 year, or positive skin prick (OR = 2.98; 95% CI, 1.35-6.36).
After age 1 year, new-onset peanut allergies developed in 0.7% (95% CI, 0.5-1.1), and new-onset raw egg allergies in 0.09% (95% CI, 0.03-0.3) of children.
In children with food allergies, a majority of egg allergy and about one third of peanut allergy resolves by age 6 years.
The natural history of food allergies is encouraging; an ideal would be able to prevent them. Current AAP guidelines recommend starting at 6 months unless they are at “high risk” for food allergies whereas starting at 4 months might be reasonable. The French Allergy Association has now recommended all children be introduced to foods that could cause allergies starting at age 4 months. (https://mybestmedicine.com/health-news/introduce-allergens-early-say-french-allergologists/)
There is some data that introducing milk products at 2 weeks of life lowers the risk of milk allergy. The Project Viva study compared when cow’s milk was introduced and the odds of developing cow’s milk allergy. They found 3% of children introduced to cow’s milk within the first 2 weeks of life developed a milk adverse reaction in later years, compared to 5% who were introduced between 2 weeks and 6 months, and 7.5% introduced after 6 months of age. (Timing of Cow’s Milk Protein Introduction and Childhood Adverse Reactions to Cow’s Milk (jaci-inpractice.org)). This could soon be a new norm.
Preventing food allergies is far easier than treating them. While we await the American Academy of Pediatrics to update their recommendations, encourage early introduction to peanuts and eggs, along with shellfish.
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Food Allergy, Pediatric
Contributed by Frank J. Domino, August 24, 2022