This document defines food allergy as an immunological response to food that can affect multiple body systems. It describes the mechanisms of food allergy, including the immune system producing IgE antibodies that trigger an inflammatory response. It lists common types of food allergies and symptoms. Diagnosis methods like skin tests and blood tests to detect IgE antibodies are discussed. Treatment includes antihistamines and bronchodilators, while prevention focuses on food labeling and manufacturer responsibilities.

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2. ‫اعداد‬/‫الطـالب‬:
‫محــمــود‬ ‫هللا‬ ‫عـــبــد‬‫راجـــى‬
‫الجـــمهــوريـــة‬‫الــيمــنــيــه‬
‫وزارة‬‫التـــعلبيم‬‫العالى‬
‫النــــــاصر‬ ‫جـــــامـــعــة‬
‫مخـــتــبــرات‬ ‫قسم‬
Republic of Yemen
Ministry of High Education
Al- nasser University
Faculty of Medical Science
Department of Laboratory
3rd Year
‫اشراف‬:
‫د‬/‫سامــى‬‫الشرعــبى‬

3. Definition
Immunological response to food
(allergic reaction)
Affects multiple body systems:
GI
Respiratory
Skin
Cardiovascular
ETC.

4. Mechanisms of food allergy
o Allergic reactions to foods vary in severity and
can be potentially fatal.
o The immune system does not recognize as safe a
protein component of the food to which the
individual is sensitive (such as some proteins in
peanuts)- called the allergen.
o The immune system then typically produces
immunoglobulin E (IgE) antibodies to the
allergen, which trigger other cells to release
substances that cause inflammation.

5. Types of food allergy:
IgE-mediated food allergy
(immediate hypersensitivity).
Cell-mediated food allergy
(delayed hypersensitivity).

6. :Allergic reactions work
Our immune system produces immunoglobullin
E (IgE), a type of protein that works against a
specific food – antibody.
IgE attaches basophils (white blood cells) and to
mast cells, cells found in all body tissues. The
typical sites of allergic reactions include nose,
throat, lungs, skin and GI tract.
An allergic reaction to food can take place within
few minutes to an hour.

7. :Symptoms
1) The 1st symptoms usually are burning, itching, irritation of
the lips, the inside of the mouth and the throat.
2) GI symptoms such as vomiting, diarrhea or abdominal pain
after the food is digested in stomach.
3) When the food allergens enter and travel through the
bloodstream, they may cause the blood pressure to drop.
4) As the allergens reach the skin, they can cause hives or
eczema.
5) When the allergen reach the lungs, they may cause asthma.

8. Common Food Allergies:
Shelfish Fish Walnuts Peanuts
Egg Wheat Milk

9. :Diagnosis
1) Skin tests:(Scratch test)
This is a test done on the skin to identify
the allergy substance (the allergen) that is the
trigger for an allergic reaction.

10. Continue………..
2) Blood tests :
Blood tests for food allergy involve analysis of
the patient’s blood, or blood serum.
3) RAST (radioallergosorbent test):
The RAST uses radioactive or enzyme markers
to detect levels of IgE antibodies in the blood.

11. Treatment:
Pharmacotherapy:
A) Antihistamines to relieve GI symptoms,
hives, sneezing and runny nose or taking.
B) Bronchodilators to relieve asthma
symptoms.

12. Prevention:
Consumer Protections & Labeling:
Food manufacturers are generally responsible
about posting alerts concerning allergen
contamination and recalling their products.