Patient Guide to Food Allergy






Definition of Food Allergy
A food allergy is when a person’s immune system responds as if a certain food is harmful to the body. If a person eats, touches, or breathes in that food, he or she can have an allergic reaction. Most allergic reactions happen within 5 minutes to 1 hour after eating or touching the food.
The most common foods that people are allergic to are:
  • Milk and foods that contain milk, such as ice cream or butter (called dairy foods)
  • Eggs
  • Wheat
  • Soy
  • Peanuts
  • Tree nuts, such as almonds or cashews
  • Fish
  • Shellfish, such as shrimp or oysters
People can have an allergy to one or more foods. Sometimes it is hard to tell if you really have a food allergy or not. People can feel sick after eating some foods for other reasons. For example, people can get heartburn after eating spicy foods. But that is not the same as a food allergy.


Symptoms of Food Allergy
The symptoms of a food allergy can range from mild to severe. Mild symptoms can include:
  • Hives: raised, red patches of skin that are very itchy
  • Red or swollen skin
  • Itchy, watery, or swollen eyes
  • Runny nose or sneezing
Severe symptoms are also called “anaphylaxis.” They can include:
  • Swelling of the throat, or coughing a lot
  • Wheezing or trouble breathing
  • Throwing up or having diarrhea
  • Feeling dizzy or passing out
  • Death
Symptoms can differ from person to person. Also, a person can have different symptoms each time he or she has an allergic reaction. 


Test for Food Allergy
Doctors can use two types of tests to tell if you have a food allergy. You and your doctor will decide which is best for you.
  • Skin test: For a skin test, the doctor will put a drop of the food you might be allergic to on your skin and make a tiny prick in the skin. Then, he or she will watch your skin to see if you get a red, itchy bump, like a mosquito bite.
  • Blood test: Blood tests for food allergies look for antibodies (proteins) called “IgEs” that the body makes when it is having an allergic response.
Your doctor or nurse will also do an exam and talk with you. Sometimes it can be hard to figure out what food you are allergic to. Keeping a record of the foods you eat and the symptoms you have is helpful.  


Treatment of Food Allergy
The best treatment for a severe reaction is a medicine called “epinephrine.” At the hospital, doctors can give you epinephrine and other medicines to treat your symptoms. Doctors will also watch to make sure your symptoms don’t get worse.
If you have had severe reactions to foods before, your doctor might have prescribed a device called an “auto-injector.” This device has one or two shots of epinephrine that you can give yourself. Many people get an auto-injector called an “EpiPen”. You should keep your auto-injector with you at all times. Use it right away if you think you are having a severe allergic reaction.
If you have mild food allergy symptoms, your doctor may prescribe medicine to help stop your itching and hives. 


Prevention of Food Allergy
You can prevent an allergic reaction by not eating the food you are allergic to. Even a tiny bite of food can cause a big reaction. You and your doctor can make a food allergy plan that includes:
  • Knowing how to avoid the food you are allergic to by reading food labels.
  • Telling restaurants about your food allergy if you eat out.
  • Knowing when to get help for a reaction.
  • Having an epinephrine auto-injector with you at all times.
  • Wearing a medical bracelet to let others know about your allergy.
 

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