Food Allergy

Allergy is an exaggerated reaction of the immune system to certain, normally harmless environmental substances. These substances are called allergens.

Types of Food Allergy

In the case of a food allergy, there are two types: primary and secondary food allergies.

Primary food allergies usually first appear during childhood. The symptoms appear shortly after consumption (2 hours at most) of certain food substances.
In secondary food allergy, there is an underlying allergy to pollen or dust mites. Some elements in foods are similar to these allergens and may trigger allergic reactions.

Ways to prevent food allergy

In the case of a food allergy, there are two types: primary and secondary food allergies. Primary food allergies usually first appear during childhood. The symptoms appear shortly after consumption (2 hours at most) of certain food substances.
In secondary food allergy, there is an underlying allergy to pollen or dust mites. Some elements in foods are similar to these allergens and may trigger allergic reactions.

Clinical features in food allergies

EYES: redness, watery, swelling
MOUTH: Swelling of the lips, tongue, gums, and/or larynx, itching of the mouth and throat
SKIN: Rash, hives, redness, itching
STOMACH: Nausea, vomiting, abdominal pain, diarrhea, heartburn
RESPIRATORY: Nose itch, running
LUNGS: cough, tightness in the chest, wheezing breath sounds, difficulty breathing
ANAPHYLAXIS: Shock, drop in blood pressure, elevated pulse, brief unconsciousness

How a child describes allergy reaction

Put hands to mouth, pull or scratch tongues, voices may change.
May comment that:

The foods that most frequently trigger allergic reactions

Peanuts, fish, cow’s milk, wheat, and chicken eggs. Allergies to cow’s milk or chicken eggs may diminish over time as children grow up. In some cases, they may in fact be able to consume the foods after a few years. However, allergies to peanuts and fish are usually life-long.

Exercise-induced anaphylaxis

Usually occurs within two hours of eating the allergenic food. Onset is during physical activity.
Foods most frequently reported to have induced exercise-induced anaphylaxis:

• Wheat (omega-5-gliadin) and other grains
• Shellfish (shrimp; oysters)
• Chicken
• Squid
• Peaches and other fruits
• Nuts especially hazelnut
• Peanuts and soybeans

Hidden Allergens

The known food allergen may be hidden as an unknown ingredient or contaminant:

• Eggs – baked goods, noodles
• Milk – pies, cheese
• Soy – baked goods, candy, tv dinners
• Wheat – flours, soup mixes, snacks
• Peanut – candy, baked goods, ice cream
• Fish – seafood flavors
• Identifying food Allergy.

Physician

• Medical history, physical exam
• Skin test
• Lab tests
• Oral food challenge
• Elimination diet
• Double-blind food challenge

Treatment Options:

Avoiding allergens is the safest measure when suffering from food allergies. Allergy sufferers often report that the symptoms are much lesser outside of the pollen season. Many foods especially some fruits and vegetables when heated, can be consumed without a problem.

Patients who have had severe allergic reactions to food allergens in the past (Anaphylaxis: Breathing problems, dizziness, drop in blood pressure) should keep an emergency kit with them, which usually contains an antihistamine, a corticosteroid (cortisone), and an adrenaline injection.

How can one avoid the development of food allergies?

• Identify those at risk
• Consult a doctor
• Consider breast feeding
• Maternal diet avoiding eggs, cow milk, peanuts, fish.

Children and Food Allergy

For babies, discuss formula options with doctor
Don’t introduce solid foods too early – wait about 6 months
Wait on foods with common allergens – Cow milk – age 1, Eggs – age 2, Peanuts, nuts, or fish – age 3

Differentiate food intolerance and allergy

Food intolerance is more common than allergies and is often misconceived as a food allergy. It is a physiological response to the chemicals in food. There is no immune response and no life-threatening effects. Usually one develops Bloating, gas, abdominal discomfort

Following are the intolerance events:

• Food poisoning
• Histamine toxicity (happens during the consumption of cheese, wine, and fish)
• Lactose intolerance
• Food additives (MSG in tastemakers)
• Gluten intolerance
• Corn products
• In case of true allergy – avoid food (this prevents the reactions in the immune system)
• Intolerance – a small amount is ok (usually tolerated by the digestive system)

Being safe from food allergies

On the processed food package, read the ingredient lists of food products carefully. This will
help you to trace the allergens in the food (e.g. nuts).

For people with food allergies, it can often be difficult to identify the trigger. Hence maintain an allergy book, which will help you to remember or someone else to identify substances causing allergies in you.

If you have an allergic reaction to fruit, heat it before eating. Some allergens can be destroyed this way, which can make the fruit more tolerable for you.

Resources

• Food Allergy and Anaphylaxis Network (FAAN)
• American Academy of Allergy, Asthma, and Immunology
• Food and Drug Administration
• USDA – National Agriculture Library