If your school has banned peanut butter — or any other form of peanut – from school grounds, you might find this a little confusing.  PB&J sandwiches may be a staple of the brown bag lunch, but they are also a very common trigger for people who have food allergies.  Read on to find out more about these allergies – and why the staff at your school takes them so seriously.

What is a Food Allergy?

When someone has a food allergy, their immune system reacts when a certain food is eaten.  Even a tiny amount of this food can trigger allergic signs and symptoms, which can range from mild to severe and life-threatening.  It is estimated that around 4% of adults and 4-6% of children in America have food allergies: that’s around 50 million people.

How Do You Know if You Have a Food Allergy?

There are signs and symptoms that come with both mild and severe food allergy reactions. These symptoms usually appear within 2 hours of eating, but some can appear within minutes:

  • Mild symptoms include tingling or itching of the mouth or lips, itchy skin or the development of hives or eczema, swelling of the tongue or lips which can make it difficult to talk, wheezing, a persistent cough, nasal drainage, itchy or watery eyes as well as nausea and vomiting and stomach cramps or abdominal pain.
  • Serious symptoms of an allergic food attack include swelling or constriction of the throat and subsequent difficulty breathing and a drop in blood pressure which can cause dizziness, fainting and even loss of consciousness. These symptoms indicate what is called an anaphylactic reaction and this is considered to be an emergency situation.

How Does a Food Allergy Develop?

The development of a food allergy begins when a person eats a food to which their body is sensitive.  The body sees this food as harmful and mounts an attack the way it would to a bacteria or a virus.  The immune system releases a chemical known as immunoglobulin E (or simply “IgE”) to neutralize the allergen. If you eat that same food in the future, the IgE senses its presence in your body and signals to your immune system that it needs to release chemicals called histamines. These histamines are responsible for causing the signs and symptoms of a person having an allergic reaction.

What are the Most Common Food Allergens?

Believe it or not, there are 8 specific foods/food groups which account for 90% of all allergic reactions to food. These include:

  • Shellfish
  • Fish
  • Soy
  • Peanuts
  • Tree nuts
  • Eggs
  • Milk
  • Wheat (this is not the same thing as celiac disease or gluten intolerance.

What Puts People at Risk?

While anyone can develop a food allergy, there are some factors which can put people at a greater risk. These include:

  • Family history of food allergies
  • Personal history of non-food allergies
  • Young age
  • Other diagnoses like asthma

Do Food Allergies have Complications?

Yes, there are a variety of complications associated with food allergies – and some of them are quite serious. Possible complications include:

  • Anaphylactic reactions (also called “anaphylaxis”)
  • Atopic dermatitis (eczema)
  • Migraine headaches

How Does the Doctor Know if You Have a Food Allergy?

Doctors will base a diagnosis of a food allergy on the patient’s signs and symptoms, the age of the patient (again, children are the most likely to have such an allergy), a history of other allergies (such as to pollen or pet dander) and the presence of other diagnoses, such as asthma.

Sometimes, the doctor will ask you to keep a diary where all the food that is eaten is listed as well as any signs or symptoms you have after eating. This can sometimes help to narrow down what is causing the food allergy.

Some doctors will also perform a skin prick test which can also pinpoint what is causing the allergic reaction.  During this test, a small amount of the allergen is inserted just below your skin.  Results appear within 20 minutes and the test is considered to be positive if a certain allergen produces a wheal (a raised, reddened area on the skin).  This can help the doctor to diagnose just what foods are causing you problems.

How are Food Allergies Treated?

The best way to treat a food allergy is, of course, to avoid the particular food you are allergic to. In the case of children, school staff (especially the school nurse) should be informed of the allergy, particularly if there is a history of anaphylaxis. Parents should read food labels carefully before purchasing any processed foods and also ask questions at restaurants if they are concerned about the ingredients of a certain dish.

If a child does eat a food he or she is allergic to, then treatment with oral antihistamines like Benadryl can help.

In the case of anaphylaxis, a trained person will have to administer epinephrine via an Epi-Pen – or else the child will have to self-administer if they are able. An Epi-Pen is a pre-loaded syringe which administers epinephrine when injected into the large muscles of the thigh. Epinephrine quickly reduces the swelling in the airways which is causing the shortness of breath. However, even after this has been given, a visit to the emergency room will be needed as the effects of epinephrine last only a short time and further treatment will be required once it wears off.

In short, you probably have a better understanding now of what peanut butter sandwiches are no longer the “in” thing for your lunch box!  Although food allergies are fairly rare, they are common enough that schools have had to implement protocols to ban common allergens from school to help make it a safer place for those with this condition.