Racial, Ethnic, and Socioeconomic Differences in Food Allergies in the US.

Importance: Food allergies affect approximately 8% of children and 11% of adults in the US. Racial differences in food allergy outcomes have previously been explored among Black and White children, but little is known about the distribution of food allergies across other racial, ethnic, and socioeconomic subpopulations. Objective: To estimate the national distribution of food allergies across racial, ethnic, and socioeconomic groups in the US. Design, Setting, and Participants: In this cross-sectional survey study, conducted from October 9, 2015, to September 18, 2016, a population-based survey was administered online and via telephone. A US nationally representative sample was surveyed. Participants were recruited using both probability- and nonprobability-based survey panels. Statistical analysis was performed from September 1, 2022, through April 10, 2023. Exposures: Demographic and food allergy-related participant characteristics. Main Outcomes and Measures: Stringent symptom criteria were developed to distinguish respondents with a "convincing" food allergy from those with similar symptom presentations (ie, food intolerance or oral allergy syndrome), with or without physician diagnosis. The prevalence of food allergies and their clinical outcomes, such as emergency department visits, epinephrine autoinjector use, and severe reactions, were measured across race (Asian, Black, White, and >1 race or other race), ethnicity (Hispanic and non-Hispanic), and household income. Complex survey-weighted proportions were used to estimate prevalence rates. Results: The survey was administered to 51 819 households comprising 78 851 individuals (40 443 adults and parents of 38 408 children; 51.1% women [95% CI, 50.5%-51.6%]; mean [SD] age of adults, 46.8 [24.0] years; mean [SD] age of children, 8.7 [5.2] years): 3.7% Asian individuals, 12.0% Black individuals, 17.4% Hispanic individuals, 62.2% White individuals, and 4.7% individuals of more than 1 race or other race. Non-Hispanic White individuals across all ages had the lowest rate of self-reported or parent-reported food allergies (9.5% [95% CI, 9.2%-9.9%]) compared with Asian (10.5% [95% CI, 9.1%-12.0%]), Hispanic (10.6% [95% CI, 9.7%-11.5%]), and non-Hispanic Black (10.6% [95% CI, 9.8%-11.5%]) individuals. The prevalence of common food allergens varied by race and ethnicity. Non-Hispanic Black individuals were most likely to report allergies to multiple foods (50.6% [95% CI, 46.1%-55.1%]). Asian and non-Hispanic White individuals had the lowest rates of severe food allergy reactions (Asian individuals, 46.9% [95% CI, 39.8%-54.1%] and non-Hispanic White individuals, 47.8% [95% CI, 45.9%-49.7%]) compared with individuals of other races and ethnicities. The prevalence of self-reported or parent-reported food allergies was lowest within households earning more than $150 000 per year (8.3% [95% CI, 7.4%-9.2%]). Conclusions and Relevance: This survey study of a US nationally representative sample suggests that the prevalence of food allergies was highest among Asian, Hispanic, and non-Hispanic Black individuals compared with non-Hispanic White individuals in the US. Further assessment of socioeconomic factors and corresponding environmental exposures may better explain the causes of food allergy and inform targeted management and interventions to reduce the burden of food allergies and disparities in outcomes.

Ethnicity Associations With Food Sensitization Are Mediated by Gut Microbiota Development in the First Year of Life.

BACKGROUND AND AIMS: Increasing evidence supports the role of early-life gut microbiota in developing atopic diseases, but ecological changes to gut microbiota during infancy in relation to food sensitization remain unclear. We aimed to characterize and associate these changes with the development of food sensitization in children. METHODS: In this observational study, using 16S rRNA amplicon sequencing, we characterized the composition of 2844 fecal microbiota in 1422 Canadian full-term infants. Atopic sensitization outcomes were measured by skin prick tests at age 1 year and 3 years. The association between gut microbiota trajectories, based on longitudinal shifts in community clusters, and atopic sensitization outcomes at age 1 and 3 years were determined. Ethnicity and early-life exposures influencing microbiota trajectories were initially examined, and post-hoc analyses were conducted. RESULTS: Four identified developmental trajectories of gut microbiota were shaped by birth mode and varied by ethnicity. The trajectory with persistently low Bacteroides abundance and high Enterobacteriaceae/Bacteroidaceae ratio throughout infancy increased the risk of sensitization to food allergens, particularly to peanuts at age 3 years by 3-fold (adjusted odds ratio [OR] 2.82, 95% confidence interval [CI] 1.13-7.01). A much higher likelihood for peanut sensitization was found if infants with this trajectory were born to Asian mothers (adjusted OR 7.87, 95% CI 2.75-22.55). It was characterized by a deficiency in sphingolipid metabolism and persistent Clostridioides difficile colonization. Importantly, this trajectory of depleted Bacteroides abundance mediated the association between Asian ethnicity and food sensitization. CONCLUSIONS: This study documented an association between persistently low gut Bacteroides abundance throughout infancy and sensitization to peanuts in childhood. It is the first to show a mediation role for infant gut microbiota in ethnicity-associated development of food sensitization.

Prevalence of Self-Reported Food Allergy in Six Regions of Inner Mongolia, Northern China: A Population-Based Survey.

BACKGROUND The aim of this study was to determine the prevalence of self-reported food allergy in 6 regions of Inner Mongolia, northern China. MATERIAL AND METHODS A random cluster sampling population study using a field questionnaire was distributed to 4714 individuals in 6 regions within Inner Mongolia, northern China; the study included ethnic Mongol minorities and Chinese Han populations. The questionnaire obtained data on ethnicity, age, sex, level of education, income, socioeconomic status, rural versus urban location, medical and family history, and food allergy. RESULTS There were 4441 (73.5%) completed questionnaires. The prevalence of self-reported food allergy was 18.0% (15.2% men; 20.6% women) and was age-related, being significantly greater in children compared with adults (38.7% vs. 11.9%) (P<0.001). There was a significant difference in self-reported food allergy between rural and urban populations (14.6% vs. 21.4%) (P<0.001) and between Mongolian and Han populations (20.8% vs. 15.8%) (P<0.001). Socioeconomic status, higher education level, and increased family income were significantly correlated with the prevalence of food allergy (P<0.001). Participants with allergic diseases and atopic family history were at increased risk (OR>1, P<0.001). There were no significant associations between the prevalence of food allergy and birth history, infant feeding, and duration of breastfeeding. CONCLUSIONS An increase in the prevalence of self-reported food allergy was found in the Inner Mongolia region of northern China, which was greater in urban areas compared with rural areas.

Risk Factors for Food Allergy in Early Adolescence: The SchoolNuts Study.

BACKGROUND: Despite the rising rates of anaphylaxis in older children and adolescents, risk factors for food allergy among this age group are understudied. OBJECTIVE: The objective of this study was to investigate the risk factors for current adolescent food allergy using a population-based sample. METHODS: The SchoolNuts study was a questionnaire survey among 10- to 14-year-old adolescents and their parents, followed by clinic evaluation including oral food challenge when food allergy was suspected from questionnaire response. We investigated the association between food allergy and demographic and environmental factors among a total of 4,991 adolescents using multiple logistic regression. RESULTS: Males and those with early-onset eczema had a higher risk of current food allergy in adolescence (adjusted odds ratio [aOR], 1.55; 95% confidence interval [CI], 1.12-2.15 and aOR, 14.08; 95% CI, 10.25-19.33). Those with Asian parents had increased risk compared with those with Caucasian parents (aOR, 2.82; 95% CI, 1.91-4.16), whereas being born in Asia compared with being born in Australia had decreased risk (aOR, 0.16; 95% CI, 0.04-0.67). Family history risk was higher for those with multiple members versus only 1 member (aOR, 4.62; 95% CI, 2.75-7.74 and aOR, 2.32; 95% CI, 1.36-3.97, respectively). Dog exposure during the first 5 years of life was associated with a decreased risk (aOR, 0.58; 95% CI, 0.38-0.91). CONCLUSIONS: Early-onset eczema, Asian background, and family history of allergic disease were associated with an increased risk of food allergy, whereas dog exposure in early life reduced the risk in 10- to14-year-old adolescents. Factors predicting food allergy risk in an adolescent population-based cohort appear remarkably similar to those predicting early-onset food allergy in infancy.

Low Food Allergy Prevalence Despite Delayed Introduction of Allergenic Foods-Data from the GUSTO Cohort.

BACKGROUND: There is mounting evidence that early introduction of allergenic food decreases the risk of food allergy development, especially in high-risk infants with eczema. However, there is a lack of data to suggest whether this association holds true in Asian populations. OBJECTIVE: To investigate the relationship between the timing of introduction of allergenic foods and food allergy outcomes in infants in the Growing Up in Singapore Towards healthy Outcomes (GUSTO) study. METHODS: The GUSTO cohort recruited 1152 mothers of Chinese, Malay, and Indian ethnicity who had singleton, naturally conceived pregnancies and followed their offspring prospectively. Information on demographic characteristics, child health, infant feeding practices, and a convincing history of IgE-mediated food allergy was obtained from interviewer-administered questionnaires at multiple time points. Corroborative skin prick tests to food allergens were performed at 18 and 36 months. RESULTS: Most of the infants were introduced to egg (49.6%), peanut (88.7%), and shellfish (90.2%) after age 10 months. Food allergy prevalence was, however, very low between age 12 and 48 months: egg, 0.35% to 1.8%; peanut allergy, 0.1% to 0.3%; and shellfish, 0.2% to 0.9%. There were no significant associations between the timing of introduction of allergenic foods and the development of food allergy, adjusted for confounders including breast-feeding and eczema. CONCLUSIONS: Food allergy rates in Singapore are low despite delayed introduction of allergenic foods. Early introduction of allergenic foods may thus not be necessary in populations in which overall food allergy prevalence is low, and thus infant feeding recommendations should be carefully tailored to individual populations.

Racial Differences in Food Allergy Phenotype and Health Care Utilization among US Children.

BACKGROUND: Food allergy (FA) is a prevalent condition in the United States, but little is known about its phenotypes in racial minority groups. OBJECTIVE: The objective of this study was to characterize disease phenotypes and disparities in health care utilization among African American (AA), Hispanic, and white children with FA. METHODS: We conducted a large, 2-center, retrospective cohort study of children aged 0-17 years with FA seen in allergy/immunology clinics at 2 urban tertiary care centers in the United States. We used multiple logistic regression analyses adjusted for age, gender, and insurance. RESULTS: The cohort of 817 children was composed of 35% AA, 12% Hispanic, and 53% non-Hispanic white. Compared with non-Hispanic white children, AA children had significantly higher odds of having asthma and eczema (P < .01), and significantly higher odds of allergy to wheat, soy, corn, fish, and shellfish (P < .01). Compared with non-Hispanic white children, Hispanic children had significantly higher odds of allergy to corn, fish, and shellfish (P < .01), and higher odds of eczema (P < .01), but a similar rate of asthma (P = .44). In this cohort, 55%, 18%, and 11% of AA, Hispanic, and white children were covered by Medicaid, respectively (P < .00001). Compared with whites, AA and Hispanic children had a shorter duration of follow-up for FA with an allergy specialist and higher rates of FA-related anaphylaxis and emergency department visits (P < .01). CONCLUSIONS: FA phenotypes and health care utilization differ among children of different racial and/or ethnic backgrounds in the United States that put AA and Hispanic children at higher risks of adverse outcome than white children. These differences include coexistent atopic conditions, less well recognized food allergens, and higher rates of anaphylaxis.

Socioeconomic Disparities in the Economic Impact of Childhood Food Allergy.

OBJECTIVES: We compared direct medical costs borne by the health care system and out-of-pocket costs borne by families for children with food allergy by socioeconomic characteristics. METHODS: We analyzed cross-sectional survey data collected between November 2011 and January 2012 from 1643 US caregivers with a food-allergic child. We used a 2-part regression model to estimate mean costs and identified differences by levels of household income and race or ethnicity. RESULTS: Children in the lowest income stratum incurred 2.5 times the amount of emergency department and hospitalization costs as a result of their food allergy than higher-income children ($1021, SE ±$209, vs $416, SE ±$94; P < .05). Costs incurred for specialist visits were lower in the lowest income group ($228, SE ±$21) compared with the highest income group ($311, SE ±$18; P < .01) as was spending on out-of-pocket medication costs ($117, SE ± $26, lowest income; $366, SE ±$44, highest income; P < .001). African American caregivers incurred the lowest amount of direct medical costs and spent the least on out-of-pocket costs, with average adjusted costs of $493 (SE ±$109) and $395 (SE ±$452), respectively. CONCLUSIONS: Disparities exist in the economic impact of food allergy based on socioeconomic status. Affordable access to specialty care, medications, and allergen-free foods are critical to keep all food-allergic children safe, regardless of income and race.

Topical Review: Pediatric Food Allergies Among Diverse Children.

OBJECTIVE: To present a brief review of the literature regarding potential racial/ethnic disparities in pediatric food allergy (FA). METHODS: Topical review considering data regarding FA prevalence, asthma comorbidity, epinephrine access/use, and psychosocial impact (e.g., burden, quality of life). RESULTS: Methodological variation precludes firm conclusions regarding disparities in prevalence; however, some data suggest Black children may be at particular risk. The comorbidity of FA and asthma among urban populations may increase risk of negative outcomes. There are clear racial/ethnic and socioeconomic disparities in epinephrine access and use. Psychosocial measures are frequently validated on samples that are not racially or ethnically diverse. Studies investigating FA's psychosocial impact are often composed of mostly White, non-Hispanic participants (>85% of study sample). CONCLUSIONS: Further research is needed to clarify prevalence patterns by race/ethnicity, to investigate the sources of disparity in epinephrine use, and to evaluate the differential impact of FA on diverse children.

The South African Food Sensitisation and Food Allergy population-based study of IgE-mediated food allergy: validity, safety, and acceptability.

BACKGROUND: Few studies exist on food sensitization and challenge-proven food allergy in low- and middle-income countries. OBJECTIVE: To describe the study design and methodology to recruit infants from an African population for skin prick testing and oral food challenges and the use of preliminary data to investigate the extent to which the study sample is representative of the target population. METHODS: Children 12 to 36 months old were recruited from childcare education facilities in Cape Town. Children underwent skin prick testing to foods. Those with a reactive wheal of at least 1 mm larger than the negative control and not clearly tolerant according to history to a full age-appropriate portion to at least 1 food underwent oral food challenges. Parents who chose not to participate completed a nonparticipant questionnaire. Interim analysis of at least 500 respondents was performed. Demographic features of participating children were compared with those of nonparticipants and the population demographics of the most recent Cape Town census data. RESULTS: The response rate was 60.1%, with high participation and completion rates of 96.5% and 97.5%, respectively. Demographics of the completed participant sample were similar to those of the Cape Town census. Use of a nonrespondent questionnaire indicated no selection bias in favor of increased participation of participants with allergy. No ethnic differences in sensitization or food allergy were evident. CONCLUSION: The study was safe and feasible and the recruitment was effective and representative of the target population. Future studies will aim to increase the precision of the prevalence of food sensitization and allergy, describe environmental risk factors, and include a rural black African cohort.

Food for thought: progress in understanding the causes and mechanisms of food allergy.

PURPOSE OF REVIEW: The community burden of food allergy appears to be rising, yet the causes and mechanisms are not completely understood. The purpose of this review is to provide a snapshot of the state of play of IgE food allergies, with a focus on recent advances. RECENT FINDINGS: There are still wide discrepancies regarding measures and definitions of food allergy. Even recent studies still rely on food sensitization, self-reporting, or parent-reporting rather than more robust measures. Population-based sampling strategies using objective measures are underway in some countries. Emerging data suggest substantial geographical and ethnic differences in food sensitization and allergy. Trans-cutaneous sensitization, particularly in those with eczema or filaggrin mutations, has been posited as a potential mechanism, as well as gut microbiota and genetics/epigenetics. Treatments for food allergy are still lacking, yet progress is being made, and immunotherapy appears more effective than dietary avoidance. Non-IgE food allergy remains drastically under-explored. SUMMARY: Food allergy is a complex immune-mediated disease consisting of numerous environmental/genetic/epigenetic risk factors; yet interventions are likely to be simple and cost-effective.

Growth comparison in children with and without food allergies in 2 different demographic populations.

OBJECTIVE: To examine the effects of food avoidance on the growth of children with food allergies. STUDY DESIGN: A retrospective chart review was performed for children with and without food allergies followed at 2 New York City general pediatric practices. Charts were selected based on codes from the International Classification of Diseases, 9th Revision, for well child visit, food allergy, anaphylaxis, and/or epinephrine autoinjector prescriptions. Heights and weights were obtained to calculate body mass index, height, and weight z-scores. RESULTS: Of the 9938 children seen, 439 (4.4%) were avoiding one or more foods. Of those with commercial insurance, children with food allergies were significantly shorter (mean height z-score = 0.06; P = .01) and weighed less (mean weight z-score -0.1; P = .006) than children without food allergies (mean height z-score = 0.42; mean weight z-score = 0.07). In contrast, children with food allergies and state insurance were not smaller in height or weight compared with children without food allergies. Among white subjects, there was a significant effect of food allergies on height and weight (ANOVA for height P = .012, for weight P = .0036) that was not observed for Hispanic/Latino, black, or Asian subjects. Children with allergies to milk weighed significantly less than children without milk allergies (P = .0006). CONCLUSIONS: Children with food allergies and commercial insurance have significant impairment in growth compared with those without food allergies. Additionally, children avoiding all forms of milk are shorter and weigh less than matched counterparts. Therefore, height and weight measurements should be assessed routinely in children with food allergies because there is risk for growth impairment in this population.

Prevalence of allergic sensitization in the United States: results from the National Health and Nutrition Examination Survey (NHANES) 2005-2006.

BACKGROUND: Allergic sensitization is an important risk factor for the development of atopic disease. The National Health and Nutrition Examination Survey (NHANES) 2005-2006 provides the most comprehensive information on IgE-mediated sensitization in the general US population. OBJECTIVE: We investigated clustering, sociodemographic, and regional patterns of allergic sensitization and examined risk factors associated with IgE-mediated sensitization. METHODS: Data for this cross-sectional analysis were obtained from NHANES 2005-2006. Participants aged 1 year or older (n = 9440) were tested for serum specific IgEs (sIgEs) to inhalant and food allergens; participants 6 years or older were tested for 19 sIgEs, and children aged 1 to 5 years were tested for 9 sIgEs. Serum samples were analyzed by using the ImmunoCAP System. Information on demographics and participants' characteristics was collected by means of questionnaire. RESULTS: Of the study population aged 6 years and older, 44.6% had detectable sIgEs, whereas 36.2% of children aged 1 to 5 years were sensitized to 1 or more allergens. Allergen-specific IgEs clustered into 7 groups that might have largely reflected biological cross-reactivity. Although sensitization to individual allergens and allergen types showed regional variation, the overall prevalence of sensitization did not differ across census regions, except in early childhood. In multivariate modeling young age, male sex, non-Hispanic black race/ethnicity, geographic location (census region), and reported pet avoidance measures were most consistently associated with IgE-mediated sensitization. CONCLUSIONS: The overall prevalence of allergic sensitization does not vary across US census regions, except in early life, although allergen-specific sensitization differs based on sociodemographic and regional factors. Biological cross-reactivity might be an important but not the sole contributor to the clustering of allergen-specific IgEs.

Eczema and sensitization to common allergens in the United States: a multiethnic, population-based study.

The relationship between food and environmental allergens in contributing to eczema risk is unclear on a multiethnic population level. Our purpose was to determine whether sensitization to specific dietary and environmental allergens as measured according to higher specific immunoglobulin E (IgE) levels is associated with eczema risk in children. National Health and Nutrition Examination Survey participants ages 1 to 17 years were asked whether they had ever received a diagnosis of eczema from a physician (n = 538). Total and specific serum IgE levels for four dietary allergens (egg, cow's milk, peanut, and shrimp) and five environmental allergens (dust mite, cat, dog, Aspergillus, and Alternaria) were measured. Logistic regression was used to examine the association between eczema and IgE levels. In the United States, 10.4 million children (15.6%) have a history of eczema. Eczema was more common in black children (p < 0.001) and in children from families with higher income and education (p = 0.01). The median total IgE levels were higher in children with a history of eczema than in those without (66.4 vs 50.6 kU/L, p = 0.004). In multivariate analysis adjusted for age, race, sex, family income, household education, and physician-diagnosed asthma, eczema was significantly associated with sensitization to cat dander (odds ratio [OR] = 1.2, 95% confidence interval [CI] 1.05, 1.4, p = 0.009) and dog dander (OR = 1.5, 95% CI, 1.2, 1.7, p < 0.001). After correction for multiple comparisons, only sensitization to dog dander remained significant. U.S. children with eczema are most likely to be sensitized to dog dander. Future prospective studies should further explore this relationship.

Trends in allergic conditions among children: United States, 1997-2011.

Allergic conditions are among the most common medical conditions affecting children in the United States (1-5). An allergic condition is a hypersensitivity disorder in which the immune system reacts to substances in the environment that are normally considered harmless (6,7). Food or digestive allergies, skin allergies (such as eczema), and respiratory allergies (such as hay fever) are the most common allergies among children. Allergies can affect a child's physical and emotional health and can interfere with daily activities, such as sleep, play, and attending school (8,9). A severe allergic reaction with rapid onset, anaphylaxis, can be life threatening. Foods represent the most common cause of anaphylaxis among children and adolescents (10,11). Early detection and appropriate interventions can help to decrease the negative impact of allergies on quality of life (6). This report presents recent trends in the prevalence of allergies and differences by selected sociodemographic characteristics for children under age 18 years.

Racial and ethnic disparity in food allergy in the United States: a systematic review.

BACKGROUND: The prevalence of food allergy is rising among US children. Little is known about racial/ethnic disparities in food allergy. OBJECTIVE: We performed a systematic literature review to understand racial/ethnic disparities in food allergy in the United States. METHODS: We searched PubMed/MEDLINE, Embase, and Scopus for original data about racial/ethnic disparities in the diagnosis, prevalence, treatment, or clinical course of food allergy or sensitization, with a particular focus on black (African American) race. Articles were analyzed by study methodology, racial/ethnic composition, food allergy definition, outcomes, summary statistic used, and covariate adjustment. RESULTS: Twenty of 645 identified articles met inclusion criteria. The studies used multiple differing criteria to define food allergy, including self-report, sensitization assessed by serum food-specific IgE to selected foods without corroborating history, discharge codes, clinic chart review, and event-reporting databases. None used oral food challenge. In 12 studies, black persons (primarily children) had significantly increased adjusted odds of food sensitization or significantly higher proportion or odds of food allergy by self-report, discharge codes, or clinic-based chart review than white children. Major differences in study methodology and reporting precluded calculation of a pooled estimate of effect. CONCLUSION: Sparse and methodologically limited data exist about racial/ethnic disparity in food allergy in the United States. Available data lack a common definition for food allergy and use indirect measures of allergy, not food challenge. Although data suggest an increased risk of food sensitization, self-reported allergy, or clinic-based diagnosis of food allergy among black children, no definitive racial/ethnic disparity could be found among currently available studies.

The prevalence and characteristics of food allergy in urban minority children.

BACKGROUND: Urban minority children are known to have high rates of asthma and allergic rhinitis, but little is known about food allergy in this population. OBJECTIVE: To examine the prevalence and characteristics of food allergy in an urban pediatric population. METHODS: A retrospective review of electronic medical records from children seen in the hospital-based general pediatric clinic at Mount Sinai Hospital serving East Harlem, NY, between July 1, 2008 and July 1, 2010 was performed. Charts for review were selected based on diagnosis codes for food allergy, anaphylaxis, or epinephrine autoinjector prescriptions. RESULTS: Of 9,184 children seen in this low-income, minority clinic, 3.4% (313) had a physician-documented food allergy. The most common food allergies were peanut (1.6%), shellfish (1.1%), and tree nuts (0.8%). Significantly more black children (4.7%) were affected than children of other races (2.7%, P < .0001), which consisted primarily of Hispanic and multiracial children. Anaphylaxis was most frequently documented for peanut (15.1%), fish (12.5%), and milk (11.1%). Among food-allergic children, asthma (50%), atopic dermatitis (52%), and allergic rhinitis (49%) were common. Fewer than half had confirmatory testing or evaluation by an allergy specialist, and although most had epinephrine autoinjectors prescribed, most were not prescribed food allergy action plans. CONCLUSION: This is the largest study of food allergy prevalence in an urban minority pediatric population, and 3.4% had physician-documented food allergy. Significantly more blacks were affected than children of other races. Fewer than half of food-allergic children in this population had confirmatory testing or evaluation by an allergy specialist.