About one-quarter of patients outgrow food allergies
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Key takeaways:
- 8.2% of children and 14.7% of adults outgrow their peanut allergy.
- 30.6% of men and 22% of women outgrow their allergy.
- Patients with incomes of $150,000 or more are most likely to outgrow their allergy.
SAN ANTONIO — About one-quarter of children and adults with an IgE-mediated food allergy eventually outgrew it, according to data presented at the American Academy of Allergy, Asthma & Immunology Annual Meeting.
“And there are factors that are associated with higher or lower rates of reporting that an allergy has been outgrown,” Christopher M. Warren, PhD, director of population research at the Center for Food Allergy & Asthma Research, Northwestern University Feinberg School of Medicine, told Healio.
Approximately one in 10 adults and one in 13 children currently live with one IgE-mediated food allergy or more, the researchers said, although these allergies might not persist throughout their entire lives.
“There are two ways to get a big burden of disease. You either have more of it develop at higher rates, or you keep it for longer,” Warren said.
“We’ve really been focusing on developing higher rates, but haven’t paid as much attention to whether it’s more persistent or if there are factors that are preventing people from realizing that they have outgrown the food allergy and continue to avoid it,” he continued.
In 2015 and 2016, the researchers conducted a cross-sectional population-based survey of 40,443 adults responding for themselves and 38,408 adults reporting for their children or those children responding themselves.
The researchers considered these reported food allergies to be “convincing” if symptoms were consistent with IgE-mediated reactions.
Based on the survey, 25.1% of children (95% CI, 23.6%-26.6%) and 25.5% of adults (95% CI, 22.6%-28.6%) developed an oral tolerance to one food or more, corresponding to approximately 2% of all children and 3% of all adults in the United States.
Specifically, 8.2% of children (95% CI, 5.2%-12.7%) and 14.7% of adults (95% CI, 11.9%-18%) developed a tolerance to peanut. Also, 25.6% of children (95% CI, 20.4%-31.6%) and 23.4% of adults (95% CI, 20%-27.2%) developed a tolerance to milk.
Percentages who developed a tolerance to egg included 26.7% of children (95% CI, 20.3%-34.3%) and 30% of adults (95% CI, 25.3%-35.2%). For soy, percentages who developed tolerance included 31.2% of children (95% CI, 21.8%-42.5%) and 19.9% of adults (95% CI, 15.1%-25.8%).
The study also found that adult men were more likely than adult women to report outgrowing a food allergy (30.6% vs. 22%; P < .0001). Except for wheat allergy, Black children and adults were least likely to report outgrowing the “big eight” food allergies.
“There are big access to care issues,” Warren said, adding that many people do not have access to an allergist who can confirm whether an allergy has been outgrown.
“We could also try to get better access to confirmatory testing to make sure that people who are living their lives as if they are food allergic are actually food allergic,” he said.
The researchers further found an association between earlier onset of allergy and a greater chance for developing tolerance to most food allergies among children and adults. Respondents who outgrew a food allergy were less likely to report severe reactions as well.
There was no association between comorbid atopy and risk for outgrowing an allergy, the researchers continued. Plus, children whose parents had a history of atopy were less likely to outgrow their food allergy.
Similarly, children whose parents had a history of food allergy were less likely to outgrow their food allergy too, but there was no significant difference in risk for outgrowing a food allergy between adults whose parents did and did not have a history of food allergy.
Children and adults alike with incomes of $150,000 a year or more were most likely to outgrow food allergy.
“They’re the folks who have access to therapies to induce tolerance,” Warren said. “They’re folks who have access and are willing to pay for all the copays for the clinical visits where they can find out, ‘Am I really still allergic to all these foods?’”
Based on these findings, the researchers concluded that the demographic differences that they observed among adults with food allergy may be due to between-group differences in rates of oral tolerance development.
The researchers also called for population-based efforts to assess the prevalence of clinically confirmed food allergy and development of tolerance to advance epidemiologic understanding and reduce the unnecessary avoidance of outgrown allergens.
Meanwhile, Warren encouraged physicians to confirm the food allergies that their patients report.
“Maybe it is worth a second look for the populations who have the highest burden,” he said. “Just take care to do confirmatory testing.”