This study on a nationally representative sample of US households with children expands on the results of an earlier study from 2009 to 2010 by the same group that comprehensively describes the current public health impact of childhood food allergy.

In total, surveys were completed by 51 819 US households. Half (51.1%) of the population-weighted sample was male, with 52.8% white, 24.1% Hispanic, 13.2% African American, and 3.2% Asian American. The majority of children were >5 years of age (68% were 6–17 years). Approximately 16% came from homes with annual incomes <$25 000, and 10% came from homes making >$150 000.

The survey added additional questions to the core 2009 to 2010 survey to assess emerging research issues relating to the etiology and management of food allergy and was tested on 345 pilot interviewees. Study participants were recruited first through NORC at the University of Chicago’s probability-based AmeriSpeak Panel, and then participation was expanded by using Survey Sampling International. The survey was administered in English or Spanish via telephone or the Internet. The primary outcome measure was the prevalence of overall and food-specific convincing childhood food allergy. Parent-reported food allergies were considered convincing if the most severe reaction reported to that food included at least 1 symptom on the stringent symptom list developed by an expert panel: hives, swelling (lip and/or tongue or other), difficulty swallowing, throat tightening, chest tightening, trouble breathing, wheezing, vomiting, chest pain, rapid heartbeat, fainting, and low blood pressure. A reaction was considered severe if at least 2 symptoms were reported from 2 different body systems. Isolated itchy mouth or throat after ingestion of associated foods (nuts, seafood, grains, seeds, spice, fruit, vegetable) were considered indicative of oral allergy syndrome and were not considered convincing food allergies.

The estimated prevalence of convincing childhood food allergy was 7.6%, although 11.4% of children’s caregivers reported a current food allergy before stringent symptom criteria were used to filter out those lacking a convincing history of food allergy. Food-specific rates included peanut (2.2%), milk (1.9%), shellfish (1.3%), tree nut (1.2%), egg (0.9%), fin fish (0.6%), and sesame (0.2%), with 40% of children reporting multiple food allergies. Among children with convincing food allergy, 42.3% reported severe reactions, which were more common in children with allergy to peanut (59.2%), tree nut (56.1%), and shellfish (48.7%). However, only 40.7% of children with convincing food allergy reported a current prescription for an epinephrine autoinjector. Having multiple food allergies, a current epinephrine prescription, a history of 1 or more lifetime food allergy–related emergency department visits, or comorbid asthma was also significantly associated with increased odds of a severe allergic reaction. Non-Hispanic African American children were at significantly elevated risk of having a convincing food allergy relative to non-Hispanic white children (odds ratio: 1.4 [95% confidence interval: 1.1–1.7]). Rates of other physician-diagnosed atopic conditions were significantly higher (P < .05) among children with convincing food allergy compared with all other children in the study.

Food allergy is a major public health concern, affecting ∼8% of US children or 5.6 million children. In addition to the top 8 food allergens recognized by the US Food and Drug Administration, sesame is the ninth most common food allergy and affects ∼150 000 US children. All foods have the potential to cause severe reactions; however, currently only 40% of children with convincing food allergies have an epinephrine autoinjector.

This study confirms the epidemiology of childhood food allergy previously reported; however, by eliminating children with symptoms isolated to the mouth or the gastrointestinal tract only (other than vomiting) (especially if they have a history of physician diagnosis of food allergy), the rates may be underestimated. The PRACTALL guidelines offer a standardized scoring system for allergic reactions in the context of oral food challenges and could be adapted as a survey tool. Of note, these guidelines include gastrointestinal or subjective symptoms that last longer than 40 minutes or recur consistently after 3 exposures as indicative of a convincing allergic reaction. Because the National Institutes of Health guidelines changed in 2017 to recommend early, rather than delayed, introduction of peanut into an infant’s diet, this study will serve as an important baseline to which prevalence rates may be compared.