Food Allergy
                     FOOD 
ALLERGY
Introduction
Food allergy is an immune system reaction that 
occurs soon after eating a certain food. 
Even a tiny amount of the allergy-causing food can 
trigger signs and symptoms such as digestive 
problems, hives or swollen airways. 
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Source: www.mayoclinic.org
Symptoms
• Swelling of the tongue, mouth or face
• Difficulty breathing
• Low blood pressure
• Vomiting
• Diarrhea
• Hives
• Itchy rash
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Source: www.mayoclinic.org
Anaphylaxis
• Anaphylaxis is a severe and systemic allergic 
reaction. It usually occurs soon after exposure to 
the specific allergen but can occasionally take a 
few hours to develop.
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Source: www.mayoclinic.org
Symptoms of Anaphylaxis
• a rapid fall in blood pressure
• fear or a feeling of apprehension
• an itchy, tickly throat
• nausea
• respiratory problems, such as wheezing or 
shortness of breath, which often become 
progressively worse
• itchy skin, or a rash that may spread rapidly and 
cover much of the body
• sneezing
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Source: www.medicalnewstoday.com
Common food allergy 
triggers
• The most common allergenic foods account for 
about 90%Trusted Source of all food allergies, and 
people commonly refer to them as the “big eight 
allergens.” These foods are:
• eggs
• fish
• milk
• nuts from trees, including hazelnuts, walnuts, 
cashews, and pistachios
• peanuts or groundnuts
• shellfish, including shrimps, lobster, and crab
• soybeans
• wheat
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Source: www.medicalnewstoday.com
Heredity
• The tendency of an individual to produce IgE 
against something seemingly as innocuous as 
food appears to be inherited.
• Generally, people with allergies come from 
families in which allergies are common not 
necessarily to food but perhaps allergies to 
pollen, fur, feathers, or drugs.
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Source: www.medicinenet.com
Diagnosing food allergies
To diagnose an allergy, the doctor will ask the person 
about their reactions to the food. They will want to 
know:
• what symptoms occur
• how long it takes for the reaction to begin
• which foods cause it
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Source: www.medicalnewstoday.com
Skin prick test
A healthcare professional places diluted foods onto 
the person’s arm and lightly pierces the skin. 
Any reaction, such as itching, swelling, or redness, 
indicates that the person may have an allergy. 
People may need to repeat this test several times.
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Source: www.medicalnewstoday.com
Blood test
This test looks for the presence of antibodies that 
are specific to certain food proteins and can indicate 
an allergy.
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Source: www.medicalnewstoday.com
Physician-supervised 
blinded oral food challenge
This is the most scientific method to diagnose a food 
allergy accurately. 
A physician gives the person a suspected food 
allergen in increasing amounts, monitoring for 
symptoms under close supervision. This method 
removes the chance of psychological reactions.
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Source: www.medicalnewstoday.com