Food allergy
A reproducible immune-mediated reaction to a specific food, ranging from immediate IgE-mediated urticaria or anaphylaxis to delayed non-IgE-mediated skin and gastrointestinal disease; it is distinct from non-immune food intolerance.
Definition
Food allergy is an adverse health effect arising from a specific immune response that occurs reproducibly on exposure to a given food. It may be IgE-mediated, non-IgE-mediated or mixed, and is distinct from non-immune food intolerance.
First principles
Start with the clinical pattern, not a test result
Food allergy is a reproducible adverse immune response to a particular food. The timing, symptoms, reproducibility, quantity, preparation, co-factors and response to avoidance determine whether IgE-mediated, non-IgE-mediated, mixed disease or a non-immune explanation is most likely. A positive test without a matching history indicates sensitisation, not necessarily clinical allergy.
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