Define food allergy, discuss the incidence of food allergies in Canada, symptoms seen, and
how a food allergy occurs;
Identify the nine most common causes of food allergies in Canada;
Discuss the identification of food allergies and the treatment.
A food allergy involves an immune response to a food substance (specifically the proteins in
that food) called antigens.<
In Canada, food allergies affect about 5-6% of children and about 3-4% of adults. When a person
has a food allergy, their immune system mistakes the protein in a food for being harmful, and so
the body makes antibodies called immunoglobulin E (IgE) the first time it is exposed to the
protein. Then, when the body is re-exposed to that food protein, the IgE is released, along with
histamine, which can cause reactions in the skin (e.g., hives, itching), respiratory system (e.g.,
runny nose, difficulty breathing), gastrointestinal tract (vomiting, diarrhea), cardiovascular
system (e.g., drop in blood pressure), and oral cavity (swelling of the lips/tongue, itching and
irritation of the mouth, swelling and tightening in the throat). Food allergies can be serious
enough to cause death in some cases. The most severe symptom seen is called anaphalaxis,
which affects about 1-2% of Canadians.
Anaphylaxis / Anaphylactic shock: a life threatening reaction to a food substance that affects
multiple body systems.
The symptoms of anaphylactic shock include swelling of the throat, difficulty breathing, circulatory
collapse, abdominal cramps, vomiting, diarrhea, coma and death. Symptoms tend to develop rapidly,
and to treat anaphylaxis, epinephrine (also called adrenaline) is administered via injection (e.g.,
EpiPen®) at the ini