It will be helpful for you to have some understanding of the terms that are currently being used by practitioners in the field of allergy so that you can understand the medical literature as you search for information on your child’s allergy. Understanding the terms will also pave the way for our discussion of why your child has allergies and what is happening in his or her body when an allergic reaction is occurring.
The most recent attempt at a definition of allergy adverse reactions to foods from the European Academy of Allergy and Clinical Immunology in 20011 includes the following:
• Allergy is a hypersensitivity reaction initiated by immunologic mechanisms.
• An adverse reaction to food should be called food hypersensitivity.
– When immunologic mechanisms have been demonstrated, the appropriate term is food allergy.
– If the role of IgE is highlighted, the correct term is IgE-mediated food allergy.
– All other reactions, previously sometimes referred to as “food intolerance,” should be referred to as non allergic food hypersensitivity.
• Severe, generalized allergic reactions to food can be classified as food anaphylaxis.
• Anaphylaxis is a severe, life-threatening, generalized or systemic hypersensitivity reaction.
• Atopy is a personal or familial tendency to produce IgE antibodies in response to low doses of allergens, usually proteins, and to develop typical symptoms such as asthma, hay fever symptoms (rhiniconjunctivitis) or eczema symptoms dermatitis.
Previously, the American Academy of Allergy and Clinical Immunology (AAACI) and the National Institute of Allergy and Infectious Disease (National Institutes of Health (NIH)) defined the diverse terms in use thus:
• An adverse food reaction is a generic term referring to any untoward reaction after the ingestion of a food.
• Adverse food reactions can be Food allergy or Food intolerance.
• A food allergy is the result of an abnormal immunologic response after ingestion of a food.
• A food intolerance is the result of non immunological mechanisms.
In spite of (or more likely, because of) these seemingly precise, but sometimes conflicting academic definitions, authors of research papers and articles on food allergy now frequently define their own use of the terms in any published work so that the reader is quite clear about their meaning in that specific context. In accordance with this sensible practice, I will do likewise. I have used the 1984 definition of the AAACI/NIH in all my previous publications and still find this the least confusing; I will continue that practice here. The terms anaphylaxis and atopy I use in the way they are defined by the EAACI.
