Klinik Dr ShahAn Original Article by:Dr.Shahjahan Bin Kassim

Food Allergies

Introduction
Allergies to a single food item or food group is a frequent occurrence that we may know someone who suffers from it. While food allergies occur commonly in babies and the young; in reality, it can occur at any age. The Center For Disease Control (CDC) USA estimates it affects 4-6% of children and 6% of the adult population. Common foods that one can be allergic to vary in countries; perhaps due to different diets. Some food allergies are common however across the world (Tab. 1).

Symptoms
Allergies occur when our normal healthy immune system (that normally protects us from infections) overreacts to certain proteins in food. The overactive immune system releases many chemicals designed to disable food protein. These immune chemicals are related to eating certain foods. It's not clearly understood why an individual develops food allergy all of a sudden. When a sensitive individual eats an allergic food, he/she develops the allergic symptoms usually within a few minutes. This type of immune reaction is called an immediate reaction. The reaction may be mild such as itch and tingling sensation of lips or more severe such as swelling around eyes, lip swelling and in severe cases, throat swelling. Food allergy can cause very serious reaction including breathing difficulty and even death. This is called anaphylaxis. Sadly there have been a number of accidental deaths related to food allergy in the west.

Common allergy symptoms include :

• Vomiting and/or stomach cramps
• Hives - hot swelling on the skin
• Shortness of breath
• Wheezing while breathing (non-asthmatic) *
• Repetitive cough- unable to speak without coughing *
• Shock or circulatory collapse *
• Tight, hoarse throat; trouble swallowing *
• Swelling of the tongue, affecting the ability to talk or breathe *
• Weak pulse *
• Pale or blue colouring of skin *
• Dizziness or feeling faint *

* Seek immediate medical attention if you have these symptoms -Anaphylaxis

Triggers Of Allergies

Although any food can cause an allergic reaction, these top 8 food groups account for 90% of food allergies:

Table 1

1. Egg :       

                                          

• Albumin (also spelled albumen)
• Egg (dried, powdered, solids, white, yolk)
• Lysozyme
• Mayonnaise
• Meringue (meringue powder)
• Ovalbumin
• Surimi

    

        Eggs are sometimes found in the following processed food:

• Baked goods (although some people can tolerate these foods—consult with your allergist)- Pastries
• Egg substitutes
• Ice cream
• Lecithin
• Marzipan
• Marshmallows
• Pasta
• Noodles (Egg noodles)

2. Milk :

     Cows Milk Protein Allergy (CMPA) often cause allergy in newborns and infants. Children can 

develop an allergy to 2 main proteins in cows milk- Casein & Whey. CMPA allergy children cause chronic diarrhea & vomiting when fed formula milk. Formula milk manufacturers have now developed special milk for children with CMPA allergy, such as partially hydrolyzed or extensively hydrolyzed formula. These new formulas are free from milk Casein & Whey. However, such formulas are expensive. It must be noted there is >90% similarity between cows & Goats milk- thus CMPA children should never be fed with Goats milk as a substitute.

  3. Peanuts :

      While peanut allergies are common in the west and Australia, its numbers are increasing in the developing world. Peanut allergy can provoke a life-threatening allergic reaction (Anaphylaxis) in certain individuals. While in reality, peanut belongs to the legume family, it does share its allergy with other nut families such as Brazil & Almond nut. There are many proteins in a peanut that cause allergies; the most toxic allergenic protein belongs to ARA group (Arachis hypogaea). Ara h3 protein is of particular significance in that its heat stable. Heat stable Ara h3 allergic protein does not degrade when the peanut is roasted or fried-which means roasted & fried peanut may cause more allergies than an unroasted peanut. As roasted groundnuts(peanuts) are used in many processed packaged food, one must be careful when purchasing (think pastries, cookies, candy bars, cereals & granolas). Severe anaphylactic reactions ( throat swelling,difficulty of breathing, wheezing, etc)  may occur of these food items that were accidentally consumed by a peanut-allergic individual. In addition, in rare cases, a person with a peanut allergy may also have allergies to other nuts such as almond, brazil nuts (1) Therefore, individuals suspected of peanut allergy must seek an allergist for proper investigation and management.



 4. Tree Nuts:
            Tree nuts are a group of eight nuts: almonds, Brazil nuts, cashews, hazelnuts, macadamia nuts, pecans, pistachios, and walnuts. Some individuals may develop a single nut allergy while others may develop multiple allergies (cross reactivity) to all nuts. It's best to see your allergist to determine your allergy type.

                             Source of chart : Jcionline.org

Next : Food Allergy - Part 2- Tests for Food Allergies











Bibiliography
1.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3962743/