A food allergy hypersensitivity is an abnormal response to a food that is triggered by the immune system.

Food allergies occur in about 6-7 million Americans. Experts estimate that about 5 to 8 percent of children and 1 to 2 percent of adults have food allergies.

In some cases, a food allergy may develop through excessive exposure to a certain food. The tendency for allergies may also be genetic. This risk may increase if both parents are allergic.

Food intolerance hypersensitivities are often mistaken for food allergies. They affect up to 45% of Americans and are an adverse reaction caused by the body’s inability to properly digest or metabolize certain foods. The most common is lactose intolerance, but any food or additive can be a problem.

A food allergy can be a serious condition and should be diagnosed by a physician. An allergist and dietitian can best help manage food allergies. Making a diagnosis may include:
– A complete medical history and physical examination
– A detailed food and symptom diary
– Various laboratory tests or skin tests

Most individuals with food allergies have other types of allergies, such as dust or pollen.

Any food can cause an allergic reaction, however, there are nine major food allergens: dairy products (milk), eggs; peanuts, wheat, corn, tree nuts (walnut, hazelnut, etc.); fish, shellfish, and soy. These nine foods cause more than 90% of all food allergic reactions.

Peanut and tree nut allergies affect approximately 3 million Americans and cause the most severe food-induced allergic reactions.

In infants and young children, cow’s milk, egg whites, peanuts, and soy are the most common causes of food allergy.

Allergic reactions to food can begin within minutes or occur hours after eating the food. In a very sensitive person, simply touching or smelling the food can cause an allergic reaction. Symptoms of food allergy vary among individuals. Common symptoms include:
– Swelling or itching of the lips, mouth and/or throat
– Gastrointestinal symptoms such as nausea, cramping, diarrhea and/or vomiting
– Skin irritations such as rashes, hives, itching and/or eczema
– Sneezing, runny nose, and/or shortness of breath
– In rare cases, some people experience anaphylaxis.

Anaphylactic shock is characterized by extreme difficulty in breathing, irregular heartbeat, a drop in blood
pressure and, if untreated, even death. Approximately 100 Americans, usually children, die annually from
food-induced anaphylaxis.

An individual who is allergic to a certain food might also be allergic to related foods. This is called cross reactivity. For example, people allergic to peanuts often cannot tolerate other members of the legume family of foods such as peas, beans and licorice.

Cross reactivity with foods also occurs in individuals highly sensitive to inhalant allergies. For example, during ragweed pollination season these individuals may have itching in their mouth after eating melons, especially cantaloupe, or a person with a dust mite allergy may become congested after eating shrimp or other crustaceans. 20% of the U. S. population has inhalant allergies and 45% of those have food cross reactivity issues.

Cross reactivity issues with food are often seen in individuals with a latex allergy. Bananas, chestnuts and avocados are the most common.

Food allergies and food intolerances can be managed by dietary methods. A well-planned elimination and rotation diet can provide a simpler, healthier approach to eating.

Food allergies are often managed by eliminating the allergens for a period of time. Permanently eliminating the offending foods may be the only treatment for those with severe food allergies. Those with less severe food allergies can often re-introduce foods once a food challenge has been performed by a health care professional and no symptomatology is elicited. The once eliminated food can then be rotated in the diet for no less than four days in an attempt to prevent re-sensitization. Concomitant treatment of an individuals non-food allergies can improve food allergy tolerance by reducing their priming effect.. All other foods are eaten in 4-5 day intervals. This is called a rotation diet. Foods are usually rotated according to their biological classification in food families, as food in the same family have similar antigens.

Individuals with food intolerance hypersensitivities may require permanent elimination of foods that contain the offender (example - lactose).