Pediatric Allergy

Establishment of a Cutoff Allergy Test Result to Guide Performance of Baked Milk Challenge Tests in Children with Milk Allergy

Milk allergy is among the most prevalent and important food allergies in children, requiring significant dietary restrictions and risk for accidental exposure and reactions. Fortunately, there is a high likelihood for spontaneous resolution in milk-allergic children with age. Prior to ultimate tolerance of straight milk and dairy foods, many children will first develop tolerance to baked goods where milk is a listed ingredient. This provides expanded dietary options for these children, and theoretically regular consumption of this type of baked milk may accelerate ultimate tolerance of straight milk and dairy foods. 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 milk challenges is not as strong, and an Immunocap result of 20 Ku/L or higher has been suggested as the recommended cutoff value. Sadly, in 2017, a child undergoing a baked milk food challenge test at another center died during the procedure, the first reported death ever associated with food challenge testing. After this tragic event, we propose to review our baked milk challenge experience over the four years 2015-2018 to determine the reaction rates at various Immunocap values and the safety of the procedure, in order to give parents and Allergists information to help in their decision-making, and to determine if a specific cutoff Immunocap value can be established to maximize safety.

Baked Milk Challenge Reactions (N = 42)

2016 - 2018

In general, this is a low to average reaction rate for food challenges, and a lower than average rate of severe reactions.

Baked Milk Reaction Relative to Baseline lgE Titers (N = 42)

2016 - 2018

a. If we stratify based on an Immunocap value of 20.0 Ku/L, then using 20.0 and below as the cutoff, 48 total challenges had 8 reactions, for a reaction rate of 16.7%, with no severe reactions. Above 20.0, 9 total challenges had 5 reactions, for a reaction rate of 55.6% and 3 severe reaction. As with baked egg, there was no age correlation with the reaction rates.

Based on these results, I recommend to the QI/Safety team that we will inform parents regarding these reaction rates for baked milk challenges, namely that there is a 55.6% reaction rate above 20.0 Ku/L, and a 16.7% reaction rate below 20.0 Ku/L. Most parents with children who have milk Immunocap results above 20 Ku/L will likely wait to perform such a challenge test unless the child in question has had tolerance of an accidental baked milk exposure, or if the potential benefits outweigh the risks of challenge.