Food allergies affect as many as 32 million Americans, including 26 million adults and 5.6 million children.

• Food allergy affects approximately 7.6 percent⁽²⁾ of children and 10.8 percent⁽¹⁾ of adults in the United States.

The Centers for Disease Control and Prevention (CDC) report that although food allergy is more prevalent in children⁽³⁾ than adults, many affected children can “outgrow” food allergies with age. In adults, however, food allergies tend to be life-long. Children with peanut, tree nut, seed, fish, or shellfish allergies generally maintain these allergies for life, and they comprise a large proportion of food-allergic adults.

A food allergy is an immune-mediated response to a food protein in which the body identifies certain foods as harmful and makes a specific antibody (IgE) against that food. In certain cases, other immune cells are involved. Food allergy is not the same as other adverse reactions that do not involve the immune system, such as:

• Scombroid food poisoning from spoiled fish, which mimics an allergic reaction.
• Pharmacological reactions to chemicals added to foods or that foods contain naturally (e.g., caffeine, tyramine, serotonin, alcohol, MSG) that cause symptoms such as cough, nasal stuffiness, headache, increased heart rate, or flushing but do not involve the immune system.
• Reactions without a defined cause. For example, sulfites are associated with cough and upper respiratory symptoms in some individuals.

These non-immune-mediated reactions may be referred to as an “allergy,” but “allergy” carries a very specific definition.

Nine foods account for 90 percent of serious allergic reactions:

• Egg
• Fish
• Milk
• Peanut
• Shellfish (shrimp, crayfish, lobster, crab, clam, scallop, mussels)
• Soy
• Tree nuts (walnuts, almonds, pecans, pistachios, cashews, hazelnuts, macadamia nuts, etc.)
• Wheat
• Sesame

While more than 160 foods can cause allergic reactions in people with food allergies, the law identifies the eight most common allergenic foods. ⁽⁴⁾

In infants and young children, common food allergens include:

• Cow’s milk, egg, peanut, tree nuts, soybeans, and wheat.

In adults, common food allergens include:

• Shellfish (both crustaceans and mollusks), peanuts, tree nuts, fish, and fruits and vegetables. (Fruits and vegetables frequently cause Oral Allergy Syndrome, which is explained in more detail below.)

With dietary restrictions and preferences on the rise, the term “allergy” is often used loosely. For example, a person with gluten intolerance – also a serious issue – might say she is “allergic” to gluten even though it is not a true “allergy.” People may have dietary restrictions without having a true food allergy, such as eating vegan or a diet restricted due to religious beliefs.

However, if you are allergic to a particular food, you may experience any of the following symptoms:

• Itchy mouth
• Swelling of the lips, tongue, and throat
• Vomiting, diarrhea, abdominal cramps and pain
• Hives (welts), itchy rashes
• Persistent eczema
• Tightening of the throat, trouble breathing, wheezing, coughing
• Sneezing, hoarseness, nasal congestion
• Drop in blood pressure, fainting, weak pulse
• A severe allergic reaction known as anaphylaxis.

It’s important to know the difference between food allergy and food intolerance or other adverse reactions to food and to seek a proper diagnosis and treatment from your doctor. If you or your doctor suspect a food allergy, make an appointment with a board-certified allergist for further testing. If a food allergy is confirmed, it is extremely important to continue treatment as recommended by your physician and to always carry prescribed medications.

More information about food allergies and food intolerances can be found by visiting our food allergy basics Web page.

Anaphylaxis

Anaphylaxis is a serious allergic reaction that comes on quickly and has the potential to become life-threatening. It includes a wide range of signs and symptoms that can occur alone or in combination after exposure to an allergen.

Anaphylaxis requires immediate medical treatment, including an injection of epinephrine and a visit to the emergency room. Anaphylaxis can be fatal if not treated promptly.

Sometimes a second round (or “phase”) of allergic reactions can occur after the initial anaphylactic reaction. This is called “biphasic anaphylaxis” A second reaction may happen as early as an hour after the first reaction or as long as 72 hours later (the average is 10 hours later) and can be less severe, as severe, or even more severe than the initial reaction. Up to 20 percent of people who have symptoms of anaphylaxis experience a second reaction related to the first – without any additional exposure to the allergen that caused the first allergic reaction.

Due to the risk of a second reaction, some physicians recommend observation in a hospital for up to 24 hours after the initial symptoms of anaphylaxis have been treated.

Learn more now about the signs and symptoms and treatment and management of anaphylaxis.

Oral Allergy Syndrome

Allergy to fruits and vegetables are the most common food allergies reported by adults and typically develop later in life. This type of allergy is called Oral Allergy Syndrome (OAS) or Pollen-Food Allergy Syndrome (PFAS). The reaction occurs because the proteins in some fruits and vegetables are similar to the proteins in pollen.

In most cases of OAS, symptoms only develop when eating the raw, uncooked food. The most common signs and symptoms are itching, tingling, redness, blisters, and swelling of the lips, mouth, or throat.

Food Allergy Management

Adults with food allergies often find themselves in situations that make managing food allergies difficult. This may include dinner meetings, travel, and even work environments. For adults who have recently developed an allergy, learning to navigate and adapt to this change in lifestyle can prove difficult, frustrating, and even stressful at times.

Adults commonly state they are good about “avoiding” their allergen. However, this is not adequate in managing food allergies. Due to the high-risk situations adults often find themselves placed in, it’s extremely important to continue treatment with a board-certified allergist, keep prescribed medications close at hand at all times in case of unintended exposure to allergens, and always read food labels.

There are many resources on our Web site to help adults learn how to navigate food allergies successfully. Through the support, education, and tools provided within this site and FAACT’s electronic newsletters for patrons, adults with food allergies can continue to lead fulfilling and productive lives!

Resources

• Food Allergy Basics
• Anaphylaxis
• Food Labels
• Related Conditions
• Dining Out
• Find a Support Group
• Follow FAACT Adults with Food Allergies Facebook Page

References