Food allergies affect about 4 to 6 percent of all kids under the age of 18 in the United States. Chances are, if your child does not have a food allergy, you know someone who does.
In fact, Children’s National Director of the Food Allergy Program, Hemant Prashad Sharma, MD
, said that the latest numbers suggest 1 in 13 kids have a food allergy. A food allergy is an adverse reaction to a specific food that the body reacts to as harmful, according to the Centers for Disease Control and Prevention
(CDC). The immune system in someone with food allergy
produces immunoglobulin E (IgE), an antibody, to fight the food allergen. As a result, when the person is exposed to that food, IgE binds to it and causes the release of a number of chemicals, including histamine. This leads to an allergic reaction.Common food allergens:
Food allergy symptoms:
- Cow’s milk
- Tree nuts (walnuts, pecans, hazelnuts, almonds, cashews, pistachios, and macadamia nuts)
- Skin and mucous membranes:
- Hives, redness, and swelling of the face or extremities
- Itching and swelling of the tongue, lips, mouth, and throat
- Gastrointestinal tract:
- Nausea, abdominal pain, vomiting, and diarrhea
- Respiratory system:
- Runny nose, sneezing, coughing, wheezing, and shortness of breath
- Cardiovascular system:
- Hypotension (low blood pressure), dizziness, syncope (fainting)
Any of these food allergies can lead to a severe, life-threatening reaction called anaphylaxis. It is estimated that food-induced anaphylaxis is the reason for about 125,000 emergency department visits each year.Managing Food Allergies:
Food allergies, however, are a manageable conditions and can be diagnosed even in infancy. Parents concerned that their child may have a food allergy can visit Children’s Food Allergy Program
, where their child may have one of these tests:
- Skin tests: A skin prick test is usually done on the back or forearm. A small amount of the allergen is introduced on the skin surface, and the skin is pricked. After 15 minutes, it is noted whether or not a wheal, which is a small reddish bump, is formed. If no wheal appears, it is usually considered a negative skin test. If a wheal appears, it is considered a positive skin test.
- Blood tests: Another test that may be performed is a blood test known as a radioallergosorbent test (RAST). RASTs check the IgE antibody levels in the blood for certain food allergens. While both of these tests are very good diagnostic tools, neither is 100 percent accurate and false positives and negatives are possible. The only definitive test for a food allergy involves seeing what happens after the suspect food is eaten.
- Food challenge: If the other tests are not conclusive, a food challenge may be recommended by your allergist. This involves eating gradually increasing amounts of the suspect food in a medical setting, and observing for any signs of an allergic reaction.
- Elimination diet: During an elimination diet, suspect foods are removed from the diet for approximately 3 weeks. If the symptoms cease during this time, it is likely that this food is causing the symptoms. The food is then gradually reintroduced to the diet. If the symptoms return, it can be concluded that the child is allergic to that food.
Dr. Sharma suggests that for the most accurate results, parents must be aware of their child’s history or the suspected food allergy to help guide the testing. How to treat food allergies:
The best treatment of food allergies is to stay away from foods and drinks that contain the allergen. It is important to read all of the labels on food packages and be wary of cross-contamination of foods. Your child’s doctor may prescribe epinephrine for severe anaphylactic reactions.
According to Dr. Sharma, about 80-90 percent of kids allergic to milk, wheat, eggs, and soy may grow out of their allergy, but the likelihood of outgrowing a peanut, tree nut, or seafood allergy is only 10 percent.