IntroductionTwo of the major unanswered questions in food allergy research are what makes one person, and not another, become allergic and what are the attributes of some foods and food proteins that make them more allergenic than others? Seeking to answer these questions is much more difficult than investigating the allergenic potency of inhalant or contact allergens since the proteins involved in sensitising or elicting allergic reactions may have undergone extensive modification during food processing and be presented within complex structures within food.These physicochemical changes will alter the way in which they are broken down during digestion and may modify the form in which they are taken up across the gut mucosal barrier and presented to the immune system. Certainly the structure of the food matrix can have a great impact on the elicitation of allergic reactions and fat-rich matrices may affect the kinetics of allergen release, potentiating the severity of allergic reactions (Grimshaw et al., 2003). However, because of its complex nature the impact of food processing and the food matrix on allergenicity of proteins has only recently become a subject of research. Such investigations are fraught with difficulties, not least the fact that food processing often renders food proteins insoluble in the simple salt solutions frequently employed in serological or clinical studies. As a consequence our understanding of the impact of food processing on allergenicity is limited to the more soluble and extractable residues in foods and the allergenic potential of insoluble protein complexes is virtually unstudied despite representing the vast bulk of food proteins consumed. Proteins in fabricated food structuresMuch of our understanding of the effects of food processing on food protein structure and the fabrication of different types of food structure has been gained from studying model food,

A model combining CRD with clinical background and extract-based serology is superior to CRD alone in assessing the risk of severe reactions to hazelnut, particular in ruling out severe reactions.

The accurate assessment and communication of the severity of acute allergic reactions are important to patients, clinicians, researchers, the food industry, and public health and regulatory authorities. Severity has different meanings to different stakeholders with patients and clinicians rating the significance of particular symptoms very differently. Many severity scoring systems have been generated, most focusing on the severity of reactions following exposure to a limited group of allergens. They are heterogeneous in format, none has used an accepted developmental approach, and none has been validated. Their wide range of outcome formats has led to difficulties with interpretation and application. Therefore, there is a persisting need for an appropriately developed and validated severity scoring system for allergic reactions that work across the range of allergenic triggers and address the needs of different stakeholder groups. We propose a novel approach to develop and then validate a harmonized scoring system for acute allergic reactions, based on a data-driven method that is informed by clinical and patient experience and other stakeholders' perspectives. We envisage two formats: (i) a numerical score giving a continuum from mild to severe reactions that are clinically meaningful and are useful for allergy healthcare professionals and researchers, and (ii) a three-grade-based ordinal format that is simple enough to be used and understood by other professionals and patients. Testing of reliability and validity of the new approach in a range of settings and populations will allow eventual implementation of a standardized scoring system in clinical studies and routine practice.