A Comprehensive Report on Onion Allergenic Extract (DB10548) and the Investigational Anesthetic ABP-700 (DB15411)

Part I: Onion (Allium cepa) Allergenic Extract (DB10548): A Diagnostic and Immunological Profile

1.0 Introduction to Onion as a Food Allergen

1.1 Overview

Onion (Allium cepa), a species within the Allium genus, is a vegetable cultivated and consumed globally, serving as a foundational ingredient in a vast array of culinary traditions.[1] Despite its ubiquity in the human diet, it is also a source of allergic reactions, which, while rare, can be severe.[1] The immunological response to onion is complex, capable of inducing both immediate (Type I) and delayed hypersensitivity reactions through various routes of exposure, including ingestion, direct skin contact, and inhalation of vapors during food preparation.[2]

To diagnose these allergic sensitivities, standardized allergenic extracts are employed in clinical settings. Onion Allergenic Extract (DrugBank ID: DB10548) is a non-standardized food allergenic extract derived from onion bulb tissue.[7] It is formulated for diagnostic use in skin testing to identify the presence of onion-specific immunoglobulin E (IgE) antibodies in sensitized individuals.[7] The extract is typically supplied in a phenol-preserved saline or glycerin-based solution for percutaneous or intradermal administration.[8] The diagnostic principle relies on the interaction between the allergenic proteins in the extract and IgE antibodies fixed to the surface of cutaneous mast cells. This interaction triggers mast cell degranulation, releasing histamine and other chemical mediators that produce a characteristic wheal-and-flare reaction, indicative of a positive test.[8]

1.2 Epidemiology and Prevalence