The Long Arc of Recommendations to Prevent Peanut and Egg Allergies

Our approach to preventing egg and peanut allergies has changed over the past 2 decades. At the turn of the century, the American Academy of Pediatrics (AAP) made an expert consensus recommendation that high-risk infants avoid eggs until age 2 years and peanuts until age 3 years. Unfortunately, the ensuing decade saw a substantial increase in self-reported peanut allergy prevalence, rising from 0.4% of US children in 1997 to 1.4% in 2008. As I discussed in a previous AFP Community Blog post, subsequent randomized trials found that introducing peanuts by age 6 months reduces the risk of developing a peanut allergy by age 5 years, leading to a reversal of the earlier recommendation.

In Australia, infant feeding guidelines were revised on a similar timetable as in the United States, with a 2016 guideline recommending that all infants be introduced to peanuts and eggs in the first year of life, regardless of allergy risk factors. A cross-sectional study found that the percentage of Australian infants who consumed eggs by age 6 months increased from 25% in 2007-2011 to 58% in 2018-2019, with 89% consuming eggs by age 12 months. A recent study by the same research team found that adjusted egg allergy prevalence decreased from 9.2% in 2007-2011 to 7.6% in 2018-2019. The prevalence of egg allergy in infants with eczema in the first 6 months of life also decreased from 34.6% to 21.9%.

In an accompanying editorial, Drs. Aaron Carroll and Ron Keren frankly assessed the harms of the AAP’s and other consensus guidelines that had incorrectly advised parents and guardians against early introduction of eggs in a misguided attempt to prevent allergies:

For years, pediatric guidelines in multiple countries told parents to do something that may have increased the risk of the very outcome they feared most. The deeper problem was not that strong evidence had been misinterpreted; it was that strong evidence did not yet exist. Committees faced a plausible theory, rising anxiety, and pressure to give families an answer. Unfortunately, they gave one with more confidence than the data could support.

The lesson that clinicians and expert panels should learn from this humbling experience, Carrol and Keren argued, is to avoid making strong recommendations based on weak or no evidence:

The field issued recommendations that outran the evidence, and families lived with the consequences. We owe families an honest accounting of that. And we owe it to the next generation of patients to hold ourselves to a higher standard—one that includes evidence grading so families understand the degree of certainty behind a recommendation, mandatory reassessment at regular intervals, and a commitment to funding the trials that can fill evidentiary gaps before guidance is issued rather than decades after.

In a 2023 American Family Physician article on food allergies, a key practice recommendation with an A evidence rating (consistent, good-quality patient-oriented evidence) stated that “early introduction of peanuts, cow’s milk, wheat, and cooked eggs between four and six months of age decreases the risk of developing food allergies.” According to a 2018 Cochrane review, children with egg allergies can be desensitized with oral immunotherapy (“daily, steadily increasing doses of egg protein over an extended period of time”), but 75% will experience allergy-related adverse effects, 8.4% of them serious enough to require medication.