Pediatric Allergy

Pediatric Allergy Outcomes

2019

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.

This reaction rate for 2018 is lower than that for the previous three years, at 20%, compared to a combined reaction rate for 2015-17 of 35.5%. I would like to think this was due to a behavior change of Allergists and parents in selection of candidates for baked egg challenge based on our previous data suggesting a high success rate for challenges in children with Immunocap titers 4.0 Ku/L or less, and a high reaction rate in children with Immunocap titers above 4.0 Ku/L. However, 11/25, or 44% of 2018 baked egg challenge tests were performed in children with Immunocap titers above 4.0 Ku/L, compared with 46.2% performed on children who had Immunocap titers above 4.0 Ku/L in 2017. This implies that the information presented last year had little impact on the behavior of Allergists and parents in selecting egg-allergic children for baked egg challenge tests, and that other factors resulted in the lower reaction rate in 2018.

Based on these results, I recommend to the QI/Safety team that we will continue to inform parents and remind our Allergy staff regarding these reaction rates for baked egg challenges, namely that there is a 55.8% reaction rate above 4.0 Ku/L, and a 13.8% reaction rate below 4.0 Ku/L. Most will likely wait to perform such a challenge test until their child’s egg Immunocap result drops below 4.0 Ku/L, unless the child in question has had tolerance of an accidental baked egg exposure, or if the potential benefits outweigh the risks of challenge.

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.

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.