Serum IgE Results Differ According to Indication for Peanut Allergy Testing
Sunday, March 6, 2016
South Exhibit Hall H (Convention Center)
Alyssa D. Drosdak, B.S., Kaitlyn Spears, B.S., Elizabeth A. Erwin, MD, Irene Mikhail, MD

Rationale: Children with eczema and other food allergies have a greater risk of peanut allergy, and comprise a large proportion of children tested for reasons other than a clear IgE mediated reaction. We aimed to understand the patterns in test results for children diagnosed with allergy to peanut based on indication for initial testing.

Methods: A retrospective review was conducted on 1,993 charts spanning records from 2009-2015 in the EMR at Nationwide Children’s Hospital’s outpatient allergy clinic. Data collected included demographics, indication for initial testing, and results of serum IgE and skin prick testing.

Results: Charts with “history of peanut allergy” were identified. Indications for testing included suspected IgE mediated reaction (n=281), eczema (n=125), and another food allergy (n=124). Mean age at initial allergy visit was 3.14 years. There was a slight male predominance (393 patients). Eczema patients were 1.8 times more likely (p=.05) to have peanut IgE > 15 kU/L than children with another food allergy and 4 times more likely (p=.0001) to have peanut IgE > 15 kU/L than patients with suspected IgE mediated reaction. Surprisingly, patients without a previous IgE mediated reaction were 1.7 times (p=.005) more likely to have peanut IgE > 2 kU/L. No significant differences were noted in prevalence of positive skin prick testing between IgE reaction, eczema and other food allergy patients.

Conclusions:   It is important for practitioners to be informed on the expected results of allergy tests in patients with different clinical presentations in order to consider food challenges when appropriate and reduce unnecessary food avoidance.