Food Allergies

Food Allergy Facts

  • Only 3% of adults have true food allergies.
  • Food intolerances are much more common than food allergies.
  • Up to 28% of the US population thinks that they may have a food intolerance.
  • As many as 15 million people in the US have food allergies.
  • Up to 6% of children have true food allergies.
  • Many children outgrow their food allergies.
  • Most adults do not outgrow their food allergies.
  • Eczema, allergies and asthma are all related. They are all caused by overactive immune systems.
  • Food allergies make someone go to the emergency room once every 3 minutes.
  • Once every 6 minutes, someone has a life-threatening allergic reaction to foods which is known as anaphylaxis.
  • People die of anaphylaxis.
  • If there is a history of asthma, a person with food allergies is much more likely to have a severe allergic reaction.

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What is a Food Allergy?

Allergies are caused by an overactive immune system.

When your body is exposed to certain chemicals or proteins in food, it thinks that it is being threatened by something that is actually harmless to other people.

Your body then overreacts and releases chemicals into your blood stream that cause an allergic reaction.

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What are the Most Common Food Allergies?

These 8 common food allergens account for more than 90% of food allergies.

In adults, the most common food allergies are:

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Do I have a Food Allergy?

Are you worried that you or someone you love may have a food allergy?

Here is a simple guide to helping you figure out if you might have food allergies.

What is a food allergy?

An allergic reaction to food occurs when your body overreacts to otherwise harmless proteins in the food that you have eaten. The body overreacts by triggering an immune response to the food. Specific antibodies are then released into the blood stream which causes the release of a chemical called histamine. Histamine makes blood vessels very leaky. In severe situations, it can even make breathing airways constrict. These reactions usually occur within a few minutes to a few hours of eating the offending food.

What symptoms may be signs of a food allergy?

The most common allergic reactions to foods that people have are:

Skin problems:

  1. Hives – itchy red welts that often come and go.
  2. Eczema – itchy bumpy skin rash that can appear over time.

Other reactions include:

Stomach problems:

  1. Nausea
  2. Vomiting
  3. Diarrhea
  4. Stomach aches
  5. Weight loss – usually seen in children.

Stomach problems can be also be caused by a food intolerance rather than an allergy.

What are signs of a severe allergic reaction?

Signs of a severe allergic reaction, known as anaphylaxis are:

Breathing problems:

  1. Wheezing or shortness of breath
  2. Throat swelling or tightness
  3. Swelling of the lips or tongue

Circulation problems:

  1. Low blood pressure – lightheadedness or feeling faint.
  2. Pale skin
  3. Weakness

This type of an allergic reaction can be deadly and requires immediate medical attention.

What do I do next?

If you think that you may have a food allergy, you should see an allergist. There are certain tests that can help make the diagnosis of food allergy including skin testing and blood testing.
If you are diagnosed with food allergies, they will recommend that you eliminate those foods in your diet. They may recommend carrying an epipen with you depending on the severity of your reaction as well.

What do I eat now?

First of all, just remember that you are not alone. As many as 15 million people have food allergies in the US.

There are lots of resources online including recipes and support groups.
Here are some great resources if you want to find out more about food allergies:

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How is a Food Allergy Diagnosed?

There are several important components to diagnosing a food allergy:

1. History – your doctor will ask for detailed information about your potential allergic reaction.

  • When was the food eaten?
  • How long after the food was eaten did the reaction happen?
  • What kind of reaction did you have?
  • How long did it last?
  • What made it go away?
  • Did anyone else get sick?
  • Were there any other foods or medicines that were eaten or taken around the same time?

2. Keep a diary – sometimes your doctor will ask you to put together a diary of what you eat and your reactions to it. This should include answers to the questions above. A food diary is especially helpful when multiple foods could be causing the allergic reaction.

3. Elimination diet – some doctors will ask you to exclude the food that may be causing the allergic reaction for some period of time. If the symptoms go away, this might be a sign of a food allergy. Under your doctor’s supervision, you may be asked to try the food again to see if in fact a reaction occurs. This is only used under certain safe circumstances like mild or moderate reactions (not severe reactions).

4.  Blood tests – these tests used to be called RAST (RadioAllergoSorbentTest). Most doctors now use a test called ImmunoCap Specific IG E which is more accurate. (It is still often referred to as RAST). These tests measure the level of antibodies (specifically IgE antibodies) your body has to certain substances. These tests may come back positive even if you do not have an allergy to a specific food. This is why your history is really important. If there is a positive history and a positive ImmunocCap test then it is much more likely that there is a true food allergy.

5. Skin tests – these tests measure whether or not your skin will actually react to the suspected food. It is also called a scratch test because the food is actually scratched into your skin. A positive test means that your skin does have a reaction to the food. This does not mean that you definitely have an allergy to that food. This is why your history is really important. If there is a positive history and a positive skin test then it is much more likely that there is a true food allergy.

6. Food challenge – the double blind food challenge is the gold standard for objective allergy testing. (double blind means that neither you nor your doctor knows which capsules or samples of food have the suspected allergenic food in it and which ones do not). You swallow the capsule or eat the food sample and your doctor monitors for an allergic reaction. The problem with this test is that it is time consuming. Also, it cannot be used if you have had a severe allergic reaction to food. (Please do not try this at home, it can be very dangerous! It must be done in an allergist’s office while being monitored very closely) For more information, contact your local allergist.

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What is the Treatment for Food Allergies?

The main treatment for food allergy is avoiding that food.

There are new treatments on the horizon, including oral immunotherapy for desensitization. Basically, your body is exposed to very small amounts of the food protein until your body eventually gets used to it. In small trials, it has worked for peanut allergies and milk allergies.

There is a skin patch that is being studied for peanut allergy desensitization.

There have also been studies on placing a small amount of the protein under the tongue (sublingual) as well as swallowing a small amount of the protein. They look promising.

(Please do not try this at home, it can be very dangerous! It must be done in an allergist’s office while being monitored very closely)

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