Food allergy more common in inner-city children

Food has joined the list of allergies for which inner-city children are at higher risk, according to a recent study, which found that at least 1 in 10 young children from 4 large cities had an allergy to peanuts, eggs, or milk.

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Researchers followed 516 inner-city children from Baltimore, New York, Boston, and St. Louis from birth to 5 years of age. Each year they assessed household allergen exposure, diet, and clinical history and performed a physical examination. At ages 1, 2, 3, and 5 years, they measured immunoglobulin E (IgE) levels of antibodies specific to milk, egg, and peanut.

Based on sensitization (IgE, 0.35 kU/L or higher) and clinical history, the investigators classified the children as allergic, possibly allergic, sensitized but tolerant, or not allergic/not sensitized. Only children with both elevated IgE and clinical symptoms were classified as allergic.  

Overall, 55.4% of the children studied were sensitized, and 9.9% of those children had a food allergy. Peanuts were the most common allergy (6%), followed by eggs (4.3%) and milk (2.7%). Another 17% of the sensitized children were possibly allergic, and 28.5% were sensitized but tolerant.

Boys and children with recurrent wheeze, eczema, and aeroallergen sensitization had a higher risk of food allergy, as did breastfed children. Exposure to endotoxin in the first year lowered the risk. No association was found with race or ethnicity, income, tobacco exposure, maternal stress, or early introduction of solid foods.

The incidence of food allergy was extremely high, even for this high-risk by design cohort, the researchers conclude, especially considering the strict definition of food allergy the study used and the fact that it included only 3 common allergens. Moreover, the study’s strict criterion for allergy may underestimate the actual number of allergic children.

Compared with the 1 in 10 food allergy prevalence for inner-city children, Food Allergy Research and Education puts the nationwide childhood prevalence at 1 in 13. The Centers for Disease Control and Prevention reports that food allergies in children are becoming more common.

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