New study examines potential factors related to the development of adult-onset food allergy

It's estimated that 33 million Americans have food allergies (FAs), including 5.6 million children under age 18. The cause of FAs is unknown, although researchers and FA experts have ruled out some common theories of how they develop.

A new study being presented at this year's American College of Allergy, Asthma and Immunology (ACAAI) Annual Scientific Meeting in Anaheim, Calif. shows that, among people who suffer from food allergies, common themes arose regarding when their food allergy developed and coinciding with certain events including, eating too much of the allergenic food; genetics and family history; antibiotic use; and eating too little of the allergenic food.

"Through an NIH-supported Food Allergy Prevalence Questionnaire, we collected nationally representative data for 38,408 children and 40,443 adults," said Christopher Warren, Ph.D., ACAAI member and co-author of the study. Respondents were categorized as having self-/parent-proxy reported FA, convincing FA according to reported food-allergic reaction symptoms consistent with an IgE-mediated response, as well as reported cases of convincing FA that are physician diagnosed.

"We know there are many theories about how food allergies develop, and there are many causal factors that likely contribute to the present food allergy epidemic. We have never had the opportunity to directly ask a large, national sample of food allergy patients and pediatric caregivers about the factors they noticed as related to their own food allergy development."

"When we directly engaged these food allergy patients/caregivers, nearly one in five reported that eating too much of an allergenic food coincided with their food allergy development, while 12% of adults reported that antibiotic use did. Notably, nearly one in four caregivers of children under the age of 17 reported that their child's food allergy development coincided with a viral infection."

Survey respondents were categorized as having self-/parent-proxy reported FA, convincing FA according to reported food-allergic reaction symptoms consistent with an IgE-mediated response, as well as reported cases of convincing FA that were physician diagnosed.

In adults and children with physician confirmed FA, the measures most perceived to be associated with development of FA were eating too much of the allergenic food [18.6% (95%CI:17.0-20.3)], genetics and family history [16.3% (95%CI:14.8-17.9)], antibiotic use [12.5% (95%CI:11.3-13.8)], and eating too little of the allergenic food [10.2% (95%CI:8.8-11.8)]. In populations 0-10 and 11-17 years old, respondents associated developing FA with a viral infection [23.8% (95%CI:21.1-26.7), 25.6% (95%CI:22.0-29.5)].

"We now know that eating certain allergenic foods, like peanuts, if eaten starting in infancy, can prevent peanut allergy," says Ruchi Gupta, MD, ACAAI member and senior author of the study.

"Allergists and other health care professionals can help get the word out to parents of infants and others that it's preventative to introduce certain allergenic foods early in life. For new-onset adult allergies, understanding potential triggers that may be involved with the development of an allergy is critical. Factors like infections, changes in the environment, and hormonal changes may be factors contributing to developing an allergy later in life and need more exploration."

The findings highlight important factors such as diet, genetics, family history, and infection that are believed by parents and adult patients to be associated with FA development. Understanding these perceptions can inform targeted interventions and patient education efforts to improve FA management and prevention.