Emily C. McGowan

Neighborhood poverty, urban residence, race/ethnicity, and asthma: Rethinking the inner-city asthma epidemic.

BACKGROUND Although it is thought that inner-city areas have a high burden of asthma, the prevalence of asthma in inner cities across the United States is not known. OBJECTIVE We sought to estimate the prevalence of current asthma in US children living in inner-city and non-inner-city areas and to examine whether urban residence, poverty, or race/ethnicity are the main drivers of asthma disparities. METHODS The National Health Interview Survey 2009-2011 was linked by census tract to data from the US Census and the National Center for Health Statistics. Multivariate logistic regression models adjusted for sex; age; race/ethnicity; residence in an urban, suburban, medium metro, or small metro/rural area; poverty; and birth outside the United States, with current asthma and asthma morbidity as outcome variables. Inner-city areas were defined as urban areas with 20% or more of households at below the poverty line. RESULTS We included 23,065 children living in 5,853 census tracts. The prevalence of current asthma was 12.9% in inner-city and 10.6% in non-inner-city areas, but this difference was not significant after adjusting for race/ethnicity, region, age, and sex. In fully adjusted models black race, Puerto Rican ethnicity, and lower household income but not residence in poor or urban areas were independent risk factors for current asthma. Household poverty increased the risk of asthma among non-Hispanics and Puerto Ricans but not among other Hispanics. Associations with asthma morbidity were very similar to those with prevalent asthma. CONCLUSIONS Although the prevalence of asthma is high in some inner-city areas, this is largely explained by demographic factors and not by living in an urban neighborhood.

Update on the Performance and Application of Basophil Activation Tests

The basophil activation test (BAT) is a flow-cytometry-based functional assay that assesses the degree of cell activation after exposure to a stimuli. Though no standardized technique currently exists, recent advances have improved the performance of this assay, including identification of new basophil-specific markers and comparisons of the expression of CD63 to CD203c during activation. The basophil activation test has also been validated for many IgE-mediated disease conditions, which have been extensively reviewed elsewhere. This review focuses on the most recent applications of this test to the diagnosis of allergy to drugs, foods, venoms, and pollens, and the evolving role of the BAT in monitoring immunotherapy.

Influence of early-life exposures on food sensitization and food allergy in an inner-city birth cohort

OBJECTIVE Previous data suggest that food allergy (FA) might be more common in inner-city children; however, these studies have not collected data on both sensitization and clinical reactivity or early-life exposures. METHODS Children in the Urban Environment and Childhood Asthma birth cohort were followed through age 5 years. Household exposures, diet, clinical history, and physical examinations were assessed yearly; levels of specific IgE to milk, egg, and peanut were measured at 1, 2, 3, and 5 years of age. On the basis of sensitization (IgE ≥0.35 kU/L) and clinical history over the 5-year period, children were classified as having FA or being possibly allergic, sensitized but tolerant, or not allergic/not sensitized. RESULTS Five hundred sixteen children were included. Overall, 55.4% were sensitized (milk, 46.7%; egg, 31.0%; and peanut, 20.9%), whereas 9.9% were categorized as having FA (peanut, 6.0%; egg, 4.3%; and milk, 2.7%; 2.5% to >1 food). The remaining children were categorized as possibly allergic (17.0%), sensitized but tolerant (28.5%), and not sensitized (44.6%). Eighteen (3.5%) reported reactions to foods for which IgE levels were not measured. Food-specific IgE levels were similar in children with FA versus sensitized but tolerant children, except for egg, levels of which were higher in patients with FA at ages 1 and 2 years. FA was associated with recurrent wheeze, eczema, aeroallergen sensitization, male sex, breast-feeding, and lower endotoxin exposure in year 1 but not with race/ethnicity, income, tobacco exposure, maternal stress, or early introduction of solid foods. CONCLUSIONS Even given that this was designed to be a high-risk cohort, the cumulative incidence of FA is extremely high, especially considering the strict definition of FA that was applied and that only 3 common allergens were included.

Effect of poverty, urbanization, and race/ethnicity on perceived food allergy in the United States

Food allergy is a common condition, affecting approximately 7% of children in the United States.1 Previous studies have suggested that food allergy is more prevalent among children living in urban centers than those living in rural locations,2 as well as among children of black race/ethnicity.3 The relative contributions of urbanization, neighborhood poverty, and race/ethnicity to this health disparity, however, have not yet been examined. In this study, data from the National Health Interview Survey (NHIS) were analyzed for years 2009-2011 in children younger than 17 years old. Perceived food allergy was assessed by the question, “During the past 12 months, has [your child] had any kind of food or digestive allergy?” Urbanization was assigned using the 2006 NCHS Urban-Rural Classification Scheme for Counties, and was categorized as “large central metro,” “large fringe metro (surburban),” “medium metro,” and “small metro/rural.” Neighborhood poverty was assessed by linking census tract of residence to data from the 2000 US Census, and a “poor” neighborhood was defined as one in which ≥20% of households were below the poverty level.4 “Poor” neighborhoods in “large central metro” urban classifications were considered “inner city.” Possible confounders, such as household income and access to health care were then examined. Further details regarding NHIS and these methods are included in the Online Supplement. To account for non-response and complex sampling methods, weights and survey strata were used for all analyses. Risk factors for self-reported food allergy were assessed by logistic regression, and all analyses were performed in STATA SE/11 (College Station, TX). Access to restricted data was approved by the NCHS Research Data Center (RDC), and all analyses were performed at the NCHS RDC Center in Hyattsville, Maryland. A total of 35,128 children (mean age of 8.4 years) were surveyed between 2009 and 2011. The overall prevalence of perceived food allergy over the past year was 5.1%. In unadjusted analyses, children living in poor urban neighborhoods had the lowest prevalence of perceived food allergy (3.1%; 95% CI 2.4–4.0%) (eTable 1), whereas children living in suburban neighborhoods had the highest prevalence (6.0%; 95% CI 5.4–6.8%). In analyses adjusted for gender, age, race/ethnicity, household income, geographic area, urban location, and access to healthcare services (Table 1), neighborhood-level poverty was found to be protective for perceived food allergy (OR 0.79; 95% CI 0.67–0.94; p=0.009). Similarly, in adjusted models, living in urban centers, as compared to suburban, was protective for perceived food allergy and approached significance (OR 0.84; 95% CI 0.69–1.00; p=0.054). Adjusted prevalence estimates are depicted in eTable2. Table 1 Relationship between demographic and geographic characteristics and self-reported food allergy in NHIS 2009-2011 Black race/ethnicity, compared to white race/ethnicity was an independent risk factor for perceived food allergy (OR 1.26; 95% CI 1.06–1.50; p=0.01), while Hispanic ethnicity was protective (OR 0.72; 95% CI 0.68–0.96; p<0.001). Both black and Hispanic children were more likely to live in urban centers (eTable 3). In this study, we found that perceived food allergy was least prevalent (3.1%) among those living in poor urban neighborhoods. This finding is in contrast to that reported by Gupta et al, where food allergy was found to be more prevalent in urban (9.8%) than rural (6.2%) locations.2 Similarly, in the high-risk inner city Urban Environment and Childhood Asthma (URECA) birth cohort, the cumulative incidence of food allergy by age 5, based on clinical and serologic data, was found to be at least 9.9%,5 which is higher than recently published national estimates.1 It is possible that our lower overall and inner city estimates may be the result of the fact that the URECA cohort was at high-risk for atopy and was predominantly of black race/ethnicity, and the different methods of assessment, definitions of food allergy and subject selection used among these studies. In contrast, our estimate of food allergy prevalence in poor urban areas is similar to that of Taylor-Black et al (3.4%) from a low-income, general pediatrics clinic in East Harlem, NY, where fewer than half of the children diagnosed with food allergy were evaluated by an allergist or had confirmatory allergy testing.6 As access to healthcare was associated with a higher risk of food allergy in our models, it is possible that food allergy in poor, urban communities may not be recognized as an important problem, which may contribute to the low estimate and differences by socioeconomic status and urbanicity seen in our study. If true, this would suggest a disparity in recognition of a potentially life-threatening condition among the parents, and possibly even physicians, of inner-city children, which warrants further study. Alternatively, certain common exposures in poor urban communities may be protective for food allergy but not other allergic conditions, such as asthma, which appears to be more prevalent in socioeconomically disadvantaged populations.7 For example, infant feeding practices are known to be different in inner city environments, and previous studies have shown that inner city children may be exposed to solid foods earlier than recommended.8 It is thus possible that the early introduction of allergenic foods and differences in management of this condition during the first year of life may ultimately protect against the development of food allergy in this population or change its natural history. Further study is thus needed to distinguish between under-report of food allergy in inner city populations and the presence of protective factors in poor urban environments. Although race/ethnicity, neighborhood-level poverty, and urbanization are closely related, when viewed independently through adjusted analyses in NHIS 2009-2011, black race appears to increase the risk of perceived food allergy whereas Hispanic ethnicity appears to be protective. This finding is consistent with previous national surveys, in which food allergy appears to be more prevalent among children of black race/ethnicity1,3 and trends lower among those of Hispanic race.9 The reasons for this disparity remain unclear but may be related to differences in genetic, dietary, or social factors. Our analysis is limited in that it is based on self-reported food allergy, which has been shown to overestimate the true prevalence of food allergy when confirmed by oral food challenges.10 Furthermore, a single question is used to define food allergy, which is very broad and could be answered affirmatively by individuals with other conditions, such as celiac disease and lactose intolerance. In addition, although we controlled for “access to health care” in our model, this was a crude measure, which does not capture differences in parental knowledge about food allergy or perception of health information. Similarly, there may be other unmeasured confounders, such as language barriers, that could influence the associations seen in this study. Finally, as individuals were surveyed in 2009-2011 but were assigned to 2000 census tracts in the NHIS, there is a potential for misclassification of neighborhood characteristics. In conclusion, in the population-based 2009-2011 NHIS, we found a low prevalence of perceived food allergy in urban impoverished children, while again noting that black race/ethnicity appears to be a risk factor for this condition whereas Hispanic ethnicity appears to be protective. Whether the prevalence of food allergy is truly lower in inner city children, and if so, whether this is due to unique neighborhood-level characteristics, fragmentation of care, differences in perception of food allergy, or under-diagnosis and under-treatment remains unclear and warrants further study.

Primary prevention of food allergy in children and adults: systematic review.

D de Silva, M Geromi, S Halken; EAACI Food Allergy and Anaphylaxis Guidelines Group. Allergy. 2014;69(5):581–589 The goal of this study was to systematically review the literature on how to prevent the development of food allergy. A systematic review was performed on articles published through September 2012. Meta-analyses, randomized controlled trials, and prospective cohort studies designed to prevent food sensitization and/or the development of food allergy were identified from Medline, Embase, Cochrane, CINAHL, Web of Science, TRIP Database, …

Do Newly Built Homes Affect Rhinitis in Children? The ISAAC Phase III Study in Korea

MI Hahm, Y Chae, HJ Kwon. Allergy. 2014;69(4):479–487 The goal of this study was to identify exacerbating factors of rhinitis among Korean children. A total of 3804 Korean children, between the ages of 6 and 7 years who were included in the 2010 ISAAC (International Study of Asthma and Allergies in Childhood), were included in this study. Children were recruited from 45 elementary schools throughout Korea and were included if they had parental completion of the ISAAC questionnaire and skin prick testing to 18 aeroallergens at the time of enrollment. Rhinitis was assessed with the question, …

Impact of Intranasal Corticosteroids on Asthma Outcomes in Allergic Rhinitis: A Meta-analysis

S Lohia, RJ Schlosser, ZM Soler. Allergy. 2013;68(5):569–579 To perform an updated systematic review with meta-analysis to assess the impact of intranasal corticosteroid (INCS) medications on asthma outcomes in patients with allergic rhinitis and asthma. A systematic review and meta-analysis were performed on articles published before May 2012. Randomized controlled trials evaluating the efficacy of intranasal corticosteroids in children and adults were identified from PubMed, Cochrane, and Medline databases and were assessed for systematic …