Real-World Safety Analysis of Preschool Tree Nut Oral Immunotherapy

Abstract

Background: Our group previously described preschool peanut oral immunotherapy (OIT) in a real-world, multicenter setting, suggesting that this therapy is safe for most preschoolers.

Objective: To examine the safety and tolerability of tree nut (TN) OIT in preschoolers in the real world.

Methods: As part of a Canada-wide quality improvement project, TN-OIT (cashew/pistachio, walnut/pecan, hazelnut, almond, and macadamia nut) was performed in preschoolers who had (1) a skin prick test wheal diameter greater than or equal to 3 mm or a specific IgE level greater than or equal to 0.35 kU/L and a convincing objective IgE-mediated reaction or (2) no ingestion history and a specific IgE level greater than or equal to 5 kU/L. Dose escalations were performed every 2 to 4 weeks till a maintenance dose of 300 mg of TN protein was reached. Symptoms were recorded and classified using the modified World Allergy Organization Subcutaneous Immunotherapy Reaction Grading System (1, mildest; 5, fatal).

Results: Of the 92 patients who started TN-OIT from 2018 to 2021, 79 (85.9%) underwent single-food TN-OIT and 13 (14.1%) underwent multifood TN-OIT to 2 (10.8%) or 3 (3.3%) TNs. Eighty-nine (96.7%) patients reached maintenance, and 4 (4.3%) dropped out. Sixty-five (70.7%) patients experienced reactions during buildup: 35 (38.0%) grade 1 reactions, 30 (32.6%) grade 2 reactions, no grade 3 or 4 reactions, and 2 (2.17%) received epinephrine.

Conclusions: Preschool TN-OIT in a real-world, multicenter setting appears safe and tolerable, with results comparable with our previously reported peanut OIT findings.

Keywords: Allergy; Hypersensitivity; Oral immunotherapy; Pediatrics; Tree nuts.