Cleveland Clinic Children's and Pediatric Institute Outcomes
Effectiveness of a Cutoff Allergy Test Result to Guide Performance of Baked Egg Challenge Tests in Children with Egg Allergy
Egg allergy is among the more common food allergies in children and can result in significant dietary restrictions. Fortunately, most children with egg allergy eventually tolerate the food as they grow older. Prior to ultimate tolerance of straight eggs, many children will first develop tolerance to baked goods where egg is a listed ingredient. This provides expanded dietary options for these children, and theoretically regular consumption of this type of baked egg may accelerate ultimate tolerance of straight eggs. Food challenge testing currently represents the standard of care for assessment of food allergy status, aided by history, physical exam, percutaneous and serum allergy tests. Correlation studies comparing straight milk challenge results with serum milk-specific IgE (Immunocap method) concentrations, predict an approximate 95% likelihood for a clinical allergic reaction if an older child has an Immunocap result of >14 Ku/L, or if a child under 2 year has a result of >5 Ku/L. These represent suggestive cutoff results, above which challenge testing is not recommended without a history of recent tolerance of an accidental exposure. Similar correlative data for baked egg challenges is not as strong, and an Immunocap result as high as 20 Ku/L has been suggested as the recommended cutoff value. We propose to review our baked egg challenge experience over the four years 2015-2018 to determine the reaction rates at various Immunocap values, in order to give parents and Allergists information to help in their decision-making, and to determine if another cutoff Immunocap value is safer and more appropriate.
Baked Egg Challenge Reactions (N = 101)
2015 - 2018
Baked Egg Reaction Relative to Basleine lgE Titers (N = 101)
2015 - 2018
If we stratify based on an Immunocap value of 4.0 Ku/L, the recommended cutoff from last year’s project, then below 4.0, 58 total challenges had 8 reactions, for a reaction rate of 13.8%. Above 4.0 Ku/L, 43 total challenges had 24 reactions, for a reaction rate of 55.8%. Given this difference, 4.0 Ku/L still seems to represent a valid cutoff value. In general, this is a safe procedure, with only 7/101 challenges having reactions needing Epi, and the Immunocap results for these seven were at 1.05 Ku/L, 6.31 Ku/L, 7.39 Ku/L, 7.76 Ku/L, 18.80 Ku/L, 40.50 Ku/L, and 80.80 Ku/L. As with last year, there was no age correlation with the reaction rates.