Triggers for Home Epinephrine-Treated Reactions During Oral Immunotherapy for Food Allergy.

Background: Home reactions requiring epinephrine treatment represent a significant obstacle to oral immunotherapy (OIT) and impair treatment outcome.

Objective: To identify potential triggers for such reactions for improvement of patient safety.

Methods: All patients aged older than 3.7 years who began an open-label OIT treatment program to milk, peanut, egg, sesame, or tree nuts in the Institute of Allergy, Immunology, and Pediatric Pulmonology at Shamir Medical Center between April 2010 and March 2018 were enrolled. Information on home epinephrine-treated reactions (HETRs) during the up-dosing phase of OIT was collected from the documentation in patients' files and the reports were transmitted by email and via a web reporting system.

Results: A total 1,270 OIT treatments were included (milk 780; peanut 256; egg 63; sesame 72; and tree nuts 99). Home epinephrine was administered in 200 treatments (15.7%) and in 70 of them a second epinephrine-treated reaction occurred. The leading identified triggers for HETRs were physical exercise temporally associated with administration of home dose (20%), and dose consumption during infectious disease (16.7%), or when fatigued (13.8%). The rate of first HETRs was highest (10.1%) to doses of 500 mg protein or less and particularly to 300 mg or less. The occurrence of first HETRs was highest (35.5%) during the first and decreased to 13.8% by the last of the 4-week home-treatment phase. Second HETRs occurred in a similar rate throughout these 4 weeks. The incidence of HETRs was highest during pollen season and vacation months.

Conclusions: The identification of factors, some protocol-dependent, that trigger HETRs should assist in improving OIT safety.