Background: While several scoring systems for the severity of anaphylactic reactions have been developed, there is a lack of consensus on definition and categorisation of severity of food allergy disease as a whole.

Aim: To develop an international consensus on the severity of food allergy (DEfinition of Food Allergy Severity, DEFASE) scoring system, to be used globally.

Methods: Phase 1: We conducted a mixed-method systematic review (SR) of 11 databases for published and unpublished literature on severity of food allergy management and set up a panel of international experts.

Phase 2: Based on our findings in Phase 1, we drafted statements for a two-round modified electronic Delphi (e-Delphi) survey. A purposefully selected multidisciplinary international expert panel on food allergy (n ¼ 60) was identified and sent a structured questionnaire, including a set of statements on different domains of food allergy severity related to symptoms, health-related quality of life, and economic impact. Participants were asked to score their agreement on each statement on a 5-point Likert scale ranging from “strongly agree” to “strongly disagree”. Median scores and percentage agreements were calculated. Consensus was defined a priori as being achieved if 70% or more of panel members rated a statement as “strongly agree” to “agree” after the second round. Based on feedback, 2 additional online voting rounds were conducted.

Results: We received responses from 92% of Delphi panel members in round 1 and 85% in round 2. Consensus was achieved on the overall score and in all of the 5 specific key domains as essential components of the DEFASE score.

Conclusions: The DEFASE score is the first comprehensive grading of food allergy severity that considers not only the severity of a single reaction, but the whole disease spectrum. An international consensus has been achieved regarding a scoring system for food allergy disease. It offers an evaluation grid, which may help to rate the severity of food allergy. Phase 3 will involve validating the scoring system in research settings, and implementing it in clinical practice.

背景：虽然已经开发了几种过敏反应严重程度的评分系统，但在食物过敏疾病的整体严重程度的定义和分类方面缺乏共识。

目的：就全球使用的食物过敏严重程度（食物过敏严重程度定义，DEFASE）评分系统制定国际共识。

方法：第一阶段：我们对11个已发表和未发表的关于食物过敏严重程度管理的文献进行了混合方法系统综述 (SR)，并成立了一个国际专家小组。

第二阶段：基于我们在第一阶段的研究结果，我们起草了关于两轮改良的电子 Delphi(e-Delphi) 调查的声明。确定了一个有目的地选择的食物过敏多学科国际专家小组 (n¼60)，并发送了结构化问卷，包括一组关于与症状、健康相关生活质量和经济影响相关的食物过敏严重程度不同领域的声明。参与者被要求在5分 Likert 量表上对他们对每项声明的一致性进行评分，范围从“强烈同意”到“强烈不同意”。计算中位评分和一致性百分比。如果70%或更多的小组成员在第二轮后将声明评定为“强烈同意”至“同意”，则先验达成共识。根据反馈，进行了2轮额外的在线投票。

结果：我们收到了第1轮92%的 Delphi 小组成员和第2轮85%的回复。作为 DEFASE 评分的基本组成部分，在总体评分和所有5个特定关键领域达成了共识。

结论：DEFASE评分是食物过敏严重程度的首次综合分级，不仅考虑单一反应的严重程度，还考虑整个疾病谱。关于食物过敏性疾病的评分系统已取得国际共识。它提供了一个评估网格，可能有助于评定食物过敏的严重程度。III期研究将涉及在研究环境中验证评分系统，并在临床实践中实施。