Changes in Food-Specific IgE Over Time in the National Health and Nutrition Examination Survey (NHANES)

Abstract

Background: Food allergy prevalence appears to have recently risen, with larger increases among non-Hispanic blacks. However, it is unclear whether these trends represent shifts in recognition of food allergy or in sensitization.

Objective: The objective of this study was to determine whether sensitization to common food allergens increased in US children from 1988-1994 to 2005-2006 and whether these trends differed by race and/or ethnicity.

Methods: Food-specific immunoglobulin E (IgE; to peanut, milk, egg, and shrimp) was measured by ImmunoCAP in stored sera from subjects aged 6-19 in the National Health and Nutrition Examination Survey (NHANES) III (1988-1994) and was compared with NHANES 2005-2006. Sensitization to foods was defined as overall (IgE ≥ 0.35 kU/L), moderate level (IgE ≥ 2 kU/L), and high level (IgE ≥ commonly used 95% predictive values). Sensitization to individual and combined foods was compared between surveys, with analyses further stratified by race and/or ethnicity.

Results: A total of 7896 subjects (NHANES III: n = 4995, NHANES 2005-2006: n = 2901) were included. In NHANES III, the prevalence of food sensitization was 24.3% (95% confidence interval [CI]: 22.1-26.5) compared with 21.6% (95% CI: 19.5-23.7) in NHANES 2005-2006. There were no significant changes in the prevalence of any level of milk, egg, or peanut sensitization, but shrimp sensitization at all levels decreased markedly; overall sensitization NHANES III: 11.2% (95% CI: 10.0-12.5) versus NHANES 2005-2006: 6.1% (95% CI: 4.5-7.7). There was a trend toward the increased prevalence of moderate- and high-level sensitization to the combination of milk, egg, and peanut among non-Hispanic blacks but not other groups.

Conclusions: In contrast to our expectations, sensitization to common food allergens did not increase between the late 1980s/early 1990s and the mid-2000s among US 6-19 year olds, and in fact decreased to shrimp.

Keywords: Epidemiology; Food allergy; Food sensitization; NHANES.

Figure 1. Trends in food sensitization over time by race/ethnicity

Proportion of children ages 6–19 with overall, moderate-level, and high-level food-specific IgE levels to milk, egg, or peanut in NHANES III (red) and NHANES 2005–2006 (blue) by race/ethnicity. (A) Non-Hispanic White; (B) Non-Hispanic Black; (C) Mexican-American. Bars and whiskers represent 95% confidence intervals (CIs).