With true food allergies, an individual’s immune system will overreact to an ordinarily harmless food. Food allergy often may appear in someone who has family members with allergies, and symptoms may occur after that allergic individual consumes even a tiny amount of food.
Food intolerance refers to an abnormal response to a food that is not an allergic reaction. It differs from an allergy in that it does not involve the immune system. A perfect example of this is lactose intolerance. Individuals with this disorder experience uncomfortable abdominal symptoms after consuming dairy products.
The most common food allergens – responsible for up to 90% of all allergic reactions – are the proteins in cow milk, eggs, soy, wheat, fish, shellfish, peanuts, and tree nuts. Both skin tests and blood tests are accurate in identifying the responsible food allergens.
The most serious type of allergic reaction is called anaphylaxis, and may involve respiratory, gastrointestinal and cardiac symptoms. Respiratory symptoms may include coughing, wheezing and chest tightness, very much like asthma symptoms. Gastrointestinal symptoms of food allergies include vomiting, diarrhea and abdominal cramping, which can be severe. These symptoms can signify a serious allergic reaction.
Most mild allergic reactions can be treated with antihistamines alone. For children at risk of a serious allergic reaction, an epinephrine auto-injector is usually prescribed (EpiPen, Twinject). These should be administered as soon as a serious reaction is occurring. All persons administered an epinephrine for a serious allergic reaction should seek immediate medical attention.
Prevention of allergic food reactions is of paramount importance. In a school lunchroom, provision of a milk-free or a peanut-free table has been found to be successful at preventing unwanted exposure to the food in question. Children with food allergies should sit at the table and may be joined by any of their friends who do not have that food in their lunch box. Useful suggestions for parents and school personnel can be found at the website of the “Food Allergy and Anaphylaxis Network”.