Welcome to Food Allergy and Your Kiddo, where you will find evidence-based, practice-proven information about food allergy.
- What all can I do to prevent my child from having a reaction?
- How can I navigate social situations without my kiddo feeling alienated?
- And how do I interpret the overwhelming amount of food allergy information available online – what’s accurate and what’s not?
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A Note From Dr. Alice Hoyt
Alice Hoyt, MD
Allergy is my profession, family is my heart, Christianity is my soul.
Food Allergy is a Journey
Where ever you are on your journey, this Guide will provide you a solid foundation upon which to build your understanding of food allergy.
There are three key components to your family living your best lives with food allergy:
- A support network of family, friends, and your faith
- A board-certified allergist who is experienced in food allergy
- A discerning mind to identify and learn accurate food allergy information while ignoring sensationalized, scare-tactic stories
Food Allergy and Your Kiddo will provide you with support in all three of those areas, and this Guide will provide you with a solid foundation of what food allergy is, how it is diagnosed, and how it is managed. Nothing here is medical advice – that should only come from your kiddo’s allergist, so take what you learn in this guide and discuss your questions with your allergist.
This Guide will help you navigate the world with the added challenge of food allergy.
Food Allergy and Your Kiddo Foundations Guide for Parents
What is food allergy?
Food allergy is an inappropriate immune response to a food. A food that causes an allergic reaction is called an “allergen.” The cause of food allergy is unclear, but much of the immunologic machinery of allergy is made up of the same cells that are involved in protecting us from parasite infections. Simply put, in a kiddo with a food allergy, the immune system thinks it is protecting the body when it attacks that specific food, but that attack can be very dangerous. We will talk about treatment later in this Guide.
Food allergy disorders can be divided into three categories. These categories are based upon whether the food allergy disorder involves IgE.
IgE is a molecule found on the outsides of allergy cells, specifically mast cells. IgE binds to allergens. For example, in a boy with egg allergy, his mast cells have IgE that binds to egg protein. When that binding occurs, the IgE sends an activation signal to the cell’s nucleus. That signal triggers the cell to release chemical-filled granules, a process called “degranulation.” When the cell degranulates, those chemicals are released into the surrounding tissues and blood stream. Those chemicals spread throughout the body causing the signs and symptoms of an allergic reaction. When severe, that reaction is called anaphylaxis.
Not all food allergy disorders cause anaphylaxis. This is because not all food allergy disorders are IgE-mediated. The three categories of food allergy disorders are:
- IgE-Mediated Food Allergy
- Non-IgE-Mediated Food Allergy
- Mixed IgE and Non-IgE-Mediated Food Allergy
1. IgE-Mediated Food Allergy
IgE-mediated food allergy is the most common type of food allergy. These types of food allergy disorders can often result in anaphylaxis. Examples include classic food allergy (e.g. peanut allergy), food-dependent exercise induced anaphylaxis, food pollen syndrome, and alpha-gal allergy.
2. Non-IgE-Mediated Food Allergy
These types of food allergy disorders are less common than IgE-mediated food allergy disorders yet still wreak havoc. These disorders involve allergy cells but not IgE. These types of food allergy disorders include food protein-induced gastrointestinal disorders or, rarely, involve the lungs. Food protein induced enterocolitis syndrome (FPIES) is an example of a non-IgE-mediated food allergy. This disorder can be acute or chronic. In acute FPIES, a specific food or foods trigger profuse vomiting and, sometimes, diarrhea, which can lead to significant dehydration. That dehydration can lead to lethargy. Symptoms of chronic FPIES may include watery diarrhea as well as some vomiting, and these symptoms can lead to failure to thrive and other issues.
3. Mixed IgE and Non-IgE-Mediated Food Allergy
These types of food allergy disorders also are less common than IgE-mediated food allergy disorders yet may co-occur with IgE-mediated food allergies. They are driven by mechanisms that do and that do not include IgE. Examples of these disorders include food-induced flaring of atopic dermatitis, which involves allergic inflammation of the skin, and eosinophil esophagitis (EOE), which involves allergic inflammation of the esophagus.
Common Food Allergens
Simply stated, an “allergen” is something which you are allergic. For example, in milk allergy, the allergen is milk. Allergens are typically proteins. Allergens that cause anaphylaxis include foods, drugs, and venoms (such as bee stings). Common food allergens are:
- Tree nut
- Sesame seed
Being allergic to a food does not always mean a kiddo has to avoid the food in all its forms. For example, many children with egg and/or milk allergy can tolerate these foods when they are baked. This is because baking egg and milk heats the allergenic proteins, causing them to be less allergenic. Alternatively, roasting peanuts seems to make peanuts more allergenic compared to non-roasted forms of peanuts.
Allergy or Intolerance?
Food allergy is different than food intolerance.
The role of allergy cells differentiates a food allergy from a food intolerance. In food allergy, allergy cells are activated and then cause the symptoms of the allergic response. For example, in IgE-mediated food allergy, mast cells cause allergy symptoms by releasing chemicals – such as histamine – when the allergen binds to the mast cell. The chemicals released by mast cell cause specific bodily responses, such as hives, swelling, trouble breathing, and vomiting. A severe allergic reaction can cause blood vessels to widen, which decreases the blood pressure and can result in death. Epinephrine stops the signs and symptoms of the allergic reaction.
A food intolerance is not an immune response to a food and may be an adverse effect of a food. For example, “Dr. Hoyt, my heart rate increases when I drink coffee.” While this certainly is a response to a food, it is not a food allergy. This example is a known effect of the caffeine found in the drink. Some food intolerances, such as lactose intolerance, are driven by the lack of an enzyme to digest the food. In the case of lactose intolerance, that lack of lactase enzyme may result in bloating and other uncomfortable symptoms upon ingestion of the lactose-containing foods.