Objective: To compare food specific serum IgE measurements among common food allergens in children with food allergy in order to determine the characteristics of the measurements, their ability to discriminate between the foods associated or not associated with a presenting clinical reaction and their change over time.
Methods: A retrospective analysis was conducted of food specific serum IgE to cow milk, egg white and yolk, peanuts, almond and soy, for up to three subsequent measurements, in 291 children with food allergy. Food specific serum IgE of < 0.35 kU/L was considered negative. Their correlation with presenting symptoms was conducted for each food in 172 children.
Results: Of 1312 food specific serum IgE measurements, 69% were positive. The median [IQR] IgE for foods associated with the presenting complaint was 7.3 kU/L [2.7, 31] and for foods not associated with a clinical complaint 2.2 kU/L [0.38, 13]. The difference was statistically significant (p = 0.01) only for cow milk. Specific IgE were highest for peanuts, followed by cow milk, eggs, soy and almonds and trended upward over time.
Conclusions: In children presenting with clinical symptoms of a reaction to a food allergen, measurements of food specific serum IgE to other common food allergens are commonly positive . A rise in food specific serum IgE occurs over time.