Food allergies occur when your immune system reacts defensively to specific food proteins that are actually harmless to the body.
When eating problematic foods for the first time, the immune system responds by producing specific anti-disease antibodies (called immunoglobulin E or IgE). When you eat the food again, IgE antibodies will immediately take effect, releasing large amounts of histamine to expel "foreign invaders" from the body. Histamine is a powerful chemical that can affect the respiratory system, gastrointestinal tract, skin or cardiovascular system.
What are the symptoms of food allergy?
Symptoms of food allergies may appear almost immediately, or within two hours after you eat the food. Symptoms may include:
- A tingling sensation in the mouth
- Swelling of the tongue and throat
- Vomiting, diarrhea, or abdominal cramps
- Difficulty breathing
- Blood pressure drop
- Loss of consciousness
A serious reaction is called an allergic reaction-it can be fatal
Which foods most commonly cause allergic reactions?
There are eight foods that cause more than 90% of children's food allergies-milk, eggs, peanuts, wheat, soybeans, fish, shellfish, and nuts (such as walnuts, pecans, and almonds). In adults, 90% of food allergies are caused by peanuts, nuts, fish and shellfish.
How to diagnose food allergies?
Your doctor may perform a radioactive allergen blood test (RAST) to check the number of antibodies produced by your immune system. Elevated levels of certain types of antibodies can help your doctor recognize specific food allergies. The doctor may also perform an allergic skin test, also called a scratch test, to determine what is causing your allergic symptoms.
By letting you keep a food diary, your doctor will have a better starting point to identify foods that may trigger your allergies. You may be asked to remove all foods that may cause allergies and then add them to your diet one at a time to see if they cause any reactions. This is called the elimination and challenge diet.
How to treat food allergies?
The best way to deal with food allergies is to strictly avoid foods that cause allergic reactions. Mild reactions usually disappear without treatment. For skin rashes, antihistamines may help reduce itching and may also relieve congestion and other symptoms.
For more severe reactions, corticosteroids, such as prednisone, will help reduce swelling. In life-threatening situations, epinephrine injections can immediately begin to reverse symptoms and are the only effective treatment option. If the doctor prescribes an auto-injector for you, please bring two at any time.
How can I prepare for food allergies?
Once you and your doctor have determined which foods you should avoid, stay away from them. However, maintaining a healthy and nutritious diet is important. Ask your doctor to recommend foods that provide the necessary nutrients.
You should also understand the ingredients in processed foods. Be sure to read the label. A registered dietitian can help you learn how to read food labels to discover hidden sources of food allergens. Some lotions, hair care products, soaps and medicines may also contain foods that may trigger allergies-such as nuts or milk.
When dining out, please call ahead to find out if the staff has received training in dealing with food allergies. Tell your waiter what you need, and if you feel uncomfortable, ask to talk to the manager or chef. Order simple prepared dishes and avoid salad bars or buffets.
If you are prone to allergic reactions, ask your doctor to prescribe an epinephrine injection box and bring two with you. Let your family and colleagues know what you are allergic to and how to help if you have a reaction. If your child is allergic, make an emergency plan with their school and teacher.
If you live in a family or roommate environment where one person is allergic and the others continue to eat problematic foods, this can be tricky. Here are some tips:
- Clearly indicate "safe" or "unsafe" on food packaging and containers. Consider placing a separate shelf in the refrigerator or pantry.
- First prepare food for allergy sufferers.
- If possible, use separate utensils and cooking utensils to prepare foods with and without allergens. Otherwise wash immediately.
- Between repairing safe and problematic foods, thoroughly clean the counter and other surfaces where you prepare your meals. For certain things, such as peanuts, you may need to use spray cleaners or disinfectant wipes and dishwashing liquid.
- Some people with allergies may cause reactions to food proteins in the form of steam or steam released into the air during the cooking process. These are rare and usually mild. Make sure that sensitive people stay away from the kitchen during and 30 minutes after cooking.
- Wash your hands frequently while cooking and before and after meals.
- Scrub the table and kitchen counter after meals.