Background The national prevalence and patterns of food allergy (FA) in the United States (US) are not well understood. Objective We developed nationally representative estimates of the prevalence of and demographic risk factors for FA, and investigated associations of FA with asthma, hay fever, and eczema. Methods 8,203 participants in the National Health and Nutrition Examination Survey (NHANES) 2005–2006 had food-specific serum IgE measured to peanut, cow's milk, egg white, and shrimp. Food-specific IgE and age-based criteria were used to define Likely FA (LFA), Possible FA (PFA), and Unlikely FA (UFA), and to develop estimates of clinical FA. Self-reported data were used to evaluate demographic risk factors and associations with asthma and related conditions. Results In the US, the estimated prevalence of clinical FA was 2.5% (peanut 1.3%, milk 0.4%, egg 0.2%, shrimp 1.0%, not mutually exclusive). Risk of PFA/LFA was increased in non-Hispanic blacks (odds ratio (OR) 3.06; 95% confidence interval (CI) 2.14-4.36), males (1.87; 1.32-2.66), and children (2.04; 1.42-2.93). Study participants with doctor-diagnosed asthma (vs. no asthma) exhibited increased risk of all measures of food sensitization. Moreover, in those with LFA, the adjusted OR for current asthma (3.8; 1.5-10.7) and an emergency room (ER) visit for asthma in the past year (6.9; 2.4-19.7) were both notably increased. Conclusion Population-based serologic data on 4 foods indicate an estimated 2.5% of the US population has FA, and increased risk was found for blacks, males, and children. Additionally, FA could be an under-recognized risk factor for problematic asthma.

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 (N=9440) were tested for sIgEs to inhalant and food allergens; participants ≥6 years were tested for 19 sIgEs, and children aged 1–5 years for 9 sIgEs. Serum samples were analyzed using the ImmunoCAP System. Information on demographics and participant characteristics was collected by questionnaire. Results Of the study population aged 6 and older, 44.6% had detectable sIgEs, while 36.2% of children aged 1–5 years were sensitized to ≥1 allergen. 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 gender, 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 by sociodemographic and regional factors. Biological cross-reactivity may be an important, but not a sole, contributor to the clustering of allergen-specific IgEs. Clinical implications IgE-mediated sensitization shows clustering patterns and differs by sociodemographic and regional factors, but the overall prevalence of sensitization may not vary across US census regions.

Background The National Health and Nutrition Examination Survey (NHANES) 2005–2006 was the first population-based study to investigate levels of serum total and allergen-specific immunoglobulin E (IgE) in the general US population. Objective We estimated prevalence of allergy-related outcomes and examined relationships between serum IgE levels and these outcomes in a representative sample of the US population. Methods Data for this cross-sectional analysis were obtained from the NHANES 2005–2006. Study subjects aged 6 years and older (N=8086) had blood taken for measurement of total IgE and 19 specific IgEs against common aeroallergens, including Alternaria alternata, Aspergillus fumigatus, Bermuda grass, birch, oak, ragweed, Russian thistle, rye grass, cat dander, cockroach, dog dander, dust mite (Dermatophagoides farinae and D. pteronyssinus), mouse and rat urine proteins; and selected foods (egg white, cow’s milk, peanut, and shrimp). Serum samples were analyzed for total and allergen-specific IgEs using the Pharmacia CAP System. Information on allergy-related outcomes and demographics was collected by questionnaire. Results In the NHANES 2005–2006, 6.6% reported current hay fever and 23.5% suffered from current allergies. Allergy-related outcomes increased with increasing total IgE (adjusted ORs for a 10-fold increase in total IgE =1.86, 95% CI:1.44–2.41 for hay fever and 1.64, 95% CI: 1.41–1.91 for allergies). Elevated levels of plant-, pet-, and mold-specific IgEs contributed independently to allergy-related symptoms. The greatest increase in odds was observed for hay fever and plant-specific IgEs (adjusted OR=4.75, 95% CI:3.83–5.88). Conclusion In the US population, self-reported allergy symptoms are most consistently associated with elevated levels of plant-, pet-, and mold-specific IgEs.

Background-Exposure to the fungus Alternaria alternata is a risk factor for asthma. Few studies have examined Alternaria exposures in indoor environments.

Rationale: Inhaled endotoxin induces airway inflammation and is an established risk factor for asthma. The -2006 National Health and Nutrition Examination Survey included measures of endotoxin and allergens in homes as well as specific IgE to inhalant allergens.Objectives: To understand the relationships between endotoxin exposure, asthma outcomes, and sensitization status for 15 aeroallergens in a nationally representative sample.Methods: Participants were administered questionnaires in their homes. Reservoir dust was vacuum sampled to generate composite bedding and bedroom floor samples. We analyzed 7,450 National Health and Nutrition Examination Survey dust and quality assurance samples for their endotoxin content using extreme quality assurance measures. Data for 6,963 subjects were available, making this the largest study of endotoxin exposure to date. Log-transformed endotoxin concentrations were analyzed using logistic models and forward stepwise linear regression. Analyses were weighted to provide national prevalence estimates and unbiased variances.Measurements and Main Results: Endotoxin exposure was significantly associated with wheeze in the past 12 months, wheeze during exercise, doctor and/or emergency room visits for wheeze, and use of prescription medications for wheeze. Models adjusted for age, sex, race and/or ethnicity, and poverty-to-income ratio and stratified by allergy status showed that these relationships were not dependent upon sensitization status but were worsened among those living in poverty. Significant predictors of higher endotoxin exposures were lower family income; Hispanic ethnicity; participant age; dog(s), cat(s), cockroaches, and/or smoker(s) in the home; and carpeted floors.Conclusions: In this U.S. nationwide representative sample, higher endotoxin exposure was significantly associated with measures of wheeze, with no observed protective effect regardless of sensitization status.

Background: Environmental exposures to phthalates, particularly high-molecular-weight (HMW) phthalates, are suspected to contribute to allergy.Objective: We assessed whether phthalate metabolites are associated with allergic symptoms and sensitization in a large nationally representative sample.Methods: We used data on urinary phthalate metabolites and allergic symptoms (hay fever, rhinitis, allergy, wheeze, asthma) and sensitization from participants ≥ 6 years of age in the National Health and Nutrition Examination Survey (NHANES) 2005–2006. Allergen sensitization was defined as a positive response to at least one of 19 specific IgE antigens (≥ 0.35 kU/L). Odds ratios (ORs) per one log10 unit change in phthalate concentration were estimated using logistic regression adjusting for age, race, body mass index, gender, creatinine, and cotinine. Separate analyses were conducted for children (6–17 years of age) and adults.Results: The HMW phthalate metabolite monobenzyl phthalate (MBzP) was the only metabolite positively associated with current allergic symptoms in adults (wheeze, asthma, hay fever, and rhinitis). Mono-(3-carboxypropyl) phthalate and the sum of diethylhexyl phthalate metabolites (both representing HMW phthalate exposures) were positively associated with allergic sensitization in adults. Conversely, in children, HMW phthalate metabolites were inversely associated with asthma and hay fever. Of the low-molecular-weight phthalate metabolites, monoethyl phthalate was inversely associated with allergic sensitization in adults (OR = 0.79; 95% CI: 0.70, 0.90).Conclusion: In this cross-sectional analysis of a nationally representative sample, HMW phthalate metabolites, particularly MBzP, were positively associated with allergic symptoms and sensitization in adults, but there was no strong evidence for associations between phthalates and allergy in children 6–17 years of age.Citation: Hoppin JA, Jaramillo R, London SJ, Bertelsen RJ, Salo PM, Sandler DP, Zeldin DC. 2013. Phthalate exposure and allergy in the U.S. population: results from NHANES 2005–2006. Environ Health Perspect 121:1129–1134; http://dx.doi.org/10.1289/ehp.1206211 [Online 25 June 2013].

We characterized the prevalence of cockroach allergen exposure in a nationally representative sample of U.S. homes and assessed risk factors for elevated concentrations.DesignWe used data from the National Survey of Lead and Allergens in Housing, a population-based cross-sectional survey.ParticipantsParticipants were residents of 831 U.S. homes in the survey.Evaluations/MeasurementsWe analyzed allergen, questionnaire, and observational data of 831 U.S. homes.ResultsCockroach allergen (Bla g 1) concentrations exceed 2.0 U/g, a level associated with allergic sensitization, in 11% of U.S. living room floors and 13% of kitchen floors. Concentrations exceed 8.0 U/g, a level associated with asthma morbidity, in 3% of living room floors and 10% of kitchen floors. Elevated concentrations were observed in high-rise apartments, urban settings, pre-1940 constructions, and households with incomes < $20,000. Odds of having concentrations > 8.0 U/g were greatest when roach problems were reported or observed and increased with the number of cockroaches observed and with indications of recent cockroach activity.ConclusionsHousehold cockroach allergen exposure is characterized in a nationally representative context. The allergen is prevalent in many settings, at levels that may contribute to allergic sensitization and asthma morbidity.Relevance to Clinical or Professional PracticeLikelihood of exposure can be assessed by consideration of demographic and household determinants.

Household mouse allergen is widespread in many settings at levels that might contribute to asthma morbidity. The likelihood of exposure can be assessed by consideration of demographic and household determinants.