Finding a Path to Safety in Food Allergy Assessment of the Global Burden, Causes, Prevention, Management, and Public Policy (2017) / Chapter Skim
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3 Prevalence
3 Prevalence
Pages 59-96
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From page 59... ...
Prevalence data also are important in helping to identify relationships between risk determinants and food allergies in specific populations. Various surveys of pediatricians and family practitioners, school teachers, school nurses, and the general public generally agree that the prevalence of food allergy in children has been increasing over the past two decades.
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From page 60... ...
question: "During the past 12 months, has your child had any kind of food or digestive allergy? " Respiratory allergy prevalence: Estimated based on affirmative responses to either of the two NHIS question(s)
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From page 61... ...
Prevalence data based on systematic reviews and meta-analyses from the United States and Europe are presented first, followed by data from individual studies in all countries, where available. It should be noted that the vast majority of data on the prevalence of food allergy has been ascertained in the pediatric population, often children in the first decade of life.
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From page 62... ...
The summary of the findings of the individual studies and systematic reviews and meta-analysis used are presented in Appendix B DIFFICULTIES IN ASCERTAINING FOOD ALLERGY PREVALENCE A variety of methodologies have been employed in an attempt to determine the prevalence of food allergy in various populations.
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From page 63... ...
Food challenge Cooked/baked versus raw food. material Selection bias Selected cohort (e.g., allergy clinic based versus birth cohort)
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From page 64... ...
Timing of Survey It also is essential to note the timing of the evaluation and the type of food involved, as a survey of young children will yield a much higher prevalence of allergy to foods such as cow milk, egg, soy, or wheat than a survey conducted in the same children at age 10 years because the majority of young children will outgrow these food allergies.
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From page 65... ...
This work was not peer-reviewed so its findings are not included in this report. One of the EAACI systematic reviews and meta-analyses reviewed studies published from January 2000 through September 2012 on food allergy prevalence in Europe of eight foods or food groups (cow milk, egg, peanut, tree nuts, wheat, soy, fish, and shellfish)
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From page 66... ...
Peanut Milk Egg Fish Shellfish Tree nuts Wheat Soy (%)
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From page 67... ...
performed a systematic review and meta-analysis on the prevalence of tree nut allergy, which was defined as allergy to almond, Brazil nut, cashew, hazelnut, macadamia nut, pecan, pistachio, or walnut (McWilliam et al., 2015)
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From page 68... ...
. Studies reporting tree nut allergy based on self-report, allergic sensitization (skin tests and/or serum IgE to individual tree nuts)
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From page 69... ...
. As noted in the previous systematic review, no summary estimates of food allergy prevalence in the different racial or ethnic groups could be determined because of the heterogeneity of the surveys.
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From page 70... ...
. These surveys consisted of reports of food allergy and assessments of serum IgE antibody levels for specific foods, ambulatory care visits, and hospitalizations.
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From page 71... ...
NHANES 2005-2006 data provide a good snapshot of IgE sensitization to the three most common food allergens in the United States -- egg, cow milk, and peanut -- but as described above, sensitization does not equate with clinical reactivity and so the actual number of Americans at risk of clinical reactions to these foods cannot be determined. In the past 5 years, a few population-based, cross-sectional surveys have been conducted in an attempt to determine the prevalence and severity of food allergy in the United States.
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From page 72... ...
(2012) also reported that the prevalence of food allergy was higher in urban centers compared to rural areas, 9.8 percent versus 6.2 percent, respectively, with peanut allergy being the most prevalent in urban centers and milk the most prevalent in rural areas (Gupta et al., 2012)
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From page 73... ...
TABLE 3-4 Prevalence of Food Allergy to Various Foods Ascertained by Convincing History Plus a Physician Diagnosis with Evidence of IgE Antibody Testing to the Food or a Positive Oral Food Challenge, Children in the United States Peanut Milk Egg Fish Shellfish Tree nuts Wheat Soy (%)
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From page 74... ...
Various criteria for diagnosing peanut allergy to determine prevalence in this cohort were provided: self-reported peanut allergic reactions -- 4.6 percent; peanut allergy based on serum IgE sensitization (IgE ≥0.35 kUA7/L; as used in NHANES 2005-2006) -- 5.0 percent; peanut-IgE + prescription for epinephrine auto-injector -- 4.9 percent; peanut-IgE ≥14 kUA/L -- 2.9 percent; and peanut-IgE ≥14 kUA/L + prescription for epinephrine autoinjector -- 2.0 percent.
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From page 75... ...
Physician-diagnosed food allergy was 4.4 percent overall and ranged from 7.5 percent in Alpine and Mediterranean regions to <1 percent in Northern Europe and the Balkans. The overall prevalence rate of IgE sensitization to all foods was 15.81 percent and ranged from 23.6 percent in the Alpine region to 6.6 percent in the Northern Maritime region.
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From page 76... ...
, and food allergy confirmed by DBPCOFC -- 10.8 percent versus 4.1 percent versus 3.2 percent, respectively. They also found large differences in self-reported food allergies between the communitybased EuroPrevall cohort and those referred to allergy centers, but sensitization and DBPCOFC-proven food allergies did not differ significantly between the two groups except for milk and egg allergy.
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From page 77... ...
agreed to at least one food challenge. Fiftyfive children experienced a positive result for an overall incidence of cow milk allergy of 0.54 percent (95% CI: 0.41%-0.70%)
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From page 78... ...
In summary, a variety of studies have been conducted in European countries to ascertain prevalence of food allergy in various populations and to various food allergens. In the most ambitious study, the EuroPrevall Surveys, 8 European centers enrolled about 3,000 individuals each to conduct questionnaires, IgE sensitization tests, and DBPCOFC.
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From page 79... ...
Oral food challenges to milk were not performed, but IgE-mediated type reactions to milk were reported in 2.7 percent (95% CI: 2.1%-3.4%) of infants.
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From page 80... ...
Egg and milk allergy were the most common food allergies in infants and young children, 0.15 percent to 4.4 percent and 0.33 percent to 3.5 percent, respectively. Shellfish (crustaceans and mollusks)
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From page 81... ...
and tree nuts (0.05 percent) being the most common.
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From page 82... ...
Assuming a food allergy prevalence rate of 3 percent (3.9 percent in individuals ages 0 to 19 years and 1 percent in those with peanut allergy) , meta-analysis of 10 evaluable studies (which had low-grade evidence and a high level of heterogeneity)
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From page 83... ...
, with markedly varying estimates of anaphylaxis due to food allergy based on individual studies ranging from 0.4 percent to 39.9 percent. In children, cow milk, egg, hazelnut, peanut, kiwi, and other tree nuts were the most common triggers, and asthma and reactions in pollen-allergic patients occurring in pollen season were identified as increased risk factors for anaphylaxis.
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From page 84... ...
In the patient survey 344 of 1,059 respondents reported a history of anaphylaxis; 31 percent of these reactions were to foods, most commonly peanuts, tree nuts, and shellfish. Even though children were included in the patient survey, it had a significant bias toward an older population (median age was age 52 years)
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From page 85... ...
. Overall, peanut allergy, tree nut allergy, or both were reported in 1.4 percent of participants (95% CI: 1.2%-1.6%)
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From page 86... ...
. Clinical peanut allergy (based on positive SPT with convincing clinical history or positive OFC in the latter two cohorts)
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From page 87... ...
In general, prevalence data based on parental surveys or specialty-based practices or hospitals provide the most inflated estimates, followed by population-based surveys, sensitizationbased studies, and medical history plus sensitization-based studies. Studies incorporating OFC typically provide the lowest and most accurate assessment of true food allergy prevalence.
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From page 88... ...
No such population-wide estimates of prevalence exist in the United States. Given the difficulty of diagnosing food allergy, the committee recommends that estimation of prevalence of food allergies in general and for the specific list of priority allergens in the United States be conducted in a systematic fashion and stratified sampling be used for cost-efficiency, with frequency-weighting used to obtain population-wide estimates.
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From page 89... ...
include • versample the population of children ages 0 to 6 years, O due to the higher prevalence of food allergy in this group and the fact that environmental exposures at this age might affect food allergy development. • onsistently incorporate questions on food allergy diagno C sis as well as intake of common food allergens into ques tionnaires to capture point prevalence, change in prevalence 11 The gold standard OFC is an expensive method and must be administered in a clinic and under supervision of a trained physician.
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From page 90... ...
• I nvite a smaller subsample of participants to undergo dou ble blinded placebo-controlled OFCs. This sample should be enriched with individuals reporting food allergies and/ or positive SPT or IgE antibody tests.
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From page 91... ...
J Allergy Clin Immunol 119(4)
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From page 92... ...
2014. Peanut allergy prevalence among school-age children in a US cohort not selected for any disease.
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From page 93... ...
J Allergy Clin Immunol Pract 1(4)
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From page 94... ...
2015. The preva lence of tree nut allergy: A systematic review.
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From page 95... ...
2014. Prevalence of common food allergies in Europe: A systematic review and meta-analysis.
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From page 96... ...
J Allergy Clin Immunol Pract 3(2)
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