Allergy: Food Allergens

Food allergy affects up to 6 to 8 percent of children under the age of three and 2 percent of adults. It can cause serious illness and, in some cases, death.

Common Food Allergens

In adults, the foods that most often cause allergic reactions include

• Shellfish such as shrimp, crayfish, lobster, and crab
• Peanuts
• Tree nuts such as walnuts
• Fish
• Eggs

The most common foods that cause problems in children are

• Eggs
• Milk
• Peanuts

Tree nuts and peanuts are the leading causes of deadly food allergy reactions called anaphylaxis.

Symptoms

Food allergens are proteins within the food that enter your bloodstream after the food is digested. From there, they go to target organs, such as your skin or nose, and cause allergic reactions. An allergic reaction to food can take place within a few minutes to an hour. The process of eating and digesting food affects the timing and the location of a reaction.

• If you are allergic to a particular food, you may first feel itching in your mouth as you start to eat the food.
• After the food is digested in your stomach, you may have gastrointestinal (GI) symptoms such as vomiting, diarrhea, or pain.
• When the food allergens enter and travel through your bloodstream, they may cause your blood pressure to drop.
• As the allergens reach your skin, they can cause hives or eczema.
• When the allergens reach your lungs, they may cause asthma.

Testing for food allergies is the same as airborne allergies.

Treatment

Food allergy is treated by avoiding the foods that trigger the reaction. Once you and your health care provider have identified the foods to which you are sensitive, you must remove them from your diet. To do this, you must read the detailed ingredient lists on each food you are considering eating.

If you have eaten the allergic foods, you may take the following medicines to relieve symptoms:

• Antihistamines to relieve GI symptoms, hives, or sneezing and a runny nose.
• Bronchodilators to relieve asthma symptoms.

Anaphylaxis is a sudden, potentially fatal, allergic reaction that can involve various parts of the body (such as the respiratory tract, gastrointestinal tract, skin, and cardiovascular system). Among food allergens, peanuts and tree nuts are most likely to trigger this deadly reaction.   Anaphylaxis requires immediate administration of epinephrine (adrenaline) and possibly other emergency medical services. If you have previously been diagnosed with anaphylaxis, you should carry a syringe of epinephrine, obtained by prescription from your doctor, and be prepared to give it to yourself if you think you are getting a food allergic reaction.

Reference:

National Institute of Allergy and Infectious Diseases, USA.