Food Allergies Flashcards
Adverse Reaction to Food
3 primary reasons
- Food Poisoning
- Food Allergies
- Food Intolerance
Food Allergies
“Immune system reacts to a substance in food that it identifies as harmful”
Food Intolerance
“Adverse reaction to substance in food that does not directly involve the immune system”
Causes of Food Allergies
- Cells in the immune system recognize a food component as harmful which triggers the immune system
- Can be caused by trace amounts (Food allergies reactions are reproducible)
Development of allergic reaction to food
- Food allergen is consumed
- Antibody is formed
- Food allergen is consumed again
- Antibodies causes histamine and other substance to be released
- Allergic reaction (severe case = anaphylactic shock)
90% of all food allergies are caused by 8 foods:
- Nut
- Eggs
- Wheat
- Milk
- Peanuts
- Soy
- Shellfish
- Fish
Celiac Disease (Wheat Allergies)
- Allergy to wheat, Gluten found in wheat and other grains (barley, rye, triticale)
- Can be difficult to diagnosed since symptoms are similar to other diseases
- Awareness: Doctors are ordering diagnostic test more (rates increasing)
Why do wheat allergies differ from other allergies?
Immune system reaction to gluten is localized in the lining of the small intestine
How are Wheat Allergies treated?
Treated with gluten free diet
-Gluten free labeling has been defined as foods that contain less than 20 parts per million gluten which is the lowest level that can be detected in foods (not enough to cause a reaction generally considered safe)
Diagnosing Wheat Allergies
- Double blind Placebo control food challenge
- Immunoglobulin E (IgE)
- Skin Prick Test
Double Blind Placebo Control Food Challenge (Diagnosing Wheat Allergies)
- Done under medical supervision
- Clinic given pill or liquid form of food that is suspected allergy and placebo form without being told which is which reaction is noted
Immunoglobulin E (Diagnosing Wheat Allergies)
Protein produced by the immune system in response to an allergen
-Identification of specific types of IgE in a person blood can help identify the presence of a food allergy but often results do not identify the specific food allergen
Skin Prick Test (Diagnosing Wheat Allergies)
- Few drops of food extract are placed on the skin and the skin is then pricked, at the same time another area is pricked using water. If the area around the food skin prick becomes redder and wider than the other site it is concluded that the person might be allergic to the food tested
- Positive result is not proof positive that an allergy exist may not be reproducible
Not all allergies are forever
Infant and children may grow out of allergies to:
-Cow’s milk: 64% by age 12
-Wheat: 66% by 12
-Eggs: 37% by 10
(Food allergies that develop as adults tend to persist)
Food Intolerance Reaction
Similar reaction as food allergies
-Intolerance does not involve the immune system but by a missing or abnormal enzyme
