Benjamin Ho, M.D.
Food allergy is an immune-based disease that has become a serious health concern in the United States. With increasing numbers of children suffering food allergy, the American Academy of Pediatrics published guidelines in 2000 that advised delaying the introduction of highly allergenic foods in infants to prevent the development of future allergy: cow’s milk until age 1; eggs until age 2; and peanuts, tree nuts and fish until age 3.
Despite these guidelines, however, the incidence and prevalence of food allergy and allergic diseases in general continued to increase substantially. The number of children reported to have food or digestive allergies increased from 2.3 million in 1997 to approximately 3 million in 2008, while the Centers for Disease Control and Prevention (CDC) reports that the prevalence of food or digestive allergies among children has increased 18 percent in the past decade.
Emerging evidence suggests that the delayed introduction of solid foods may actually increase the risk of food allergy or eczema, and the early introduction of allergenic foods may prevent food allergy in infants and children. One study reported increased risk of sensitization to egg at age 5 if egg was introduced after 10 months. And another study showed that the early exposure to cow’s milk protein via formula as a supplement to breastfeeding may actually protect against cow’s milk allergy later.
With this in mind, the American Academy of Allergy, Asthma and Immunology issued new recommendations for helping prevent allergic disease through nutritional intervention. These new guidelines, released this spring, are based on numerous recent studies that support the potential benefits of early introduction of foods — and the possible detrimental effects of delaying foods.
The new recommendations are designed to help guide primary care providers, allergists, other specialists and parents through the complicated topic of food allergies. The information at right is intended to provide a starting point, but it’s important to note that parents always should talk to their children’s physician before making any dietary changes.
About Texas Children’s
Food Allergy Center
Allergists at Texas Children’s Food Allergy Center specialize in the diagnosis and treatment of food allergies. The staff takes a thorough medical history followed by a physical exam and conducts diagnostic testing and individualized treatment.
In skin testing for immediate reactions, a small amount of an extract made from the suspected food allergen is placed on the child’s back or arm. Blood tests also can help determine which foods, if any, trigger allergic symptoms. These tests can identify the level of the antigen in each food or a specific component of the food.
Although allergy skin or blood tests can help determine foods to which children are allergic, food challenges are the best way to determine if a child is allergic to a food. These are performed in a controlled setting within the Food Allergy Center with close monitoring and fast availability of medications in the event of a reaction.
Treatment options for food allergies involve strict avoidance of the food to which a child is allergic. Precautions must be taken to prevent accidental ingestion of foods with hidden ingredients. At the Food Allergy Center, each patient is given a food allergy action plan with extensive education on how to use it, along with medications, to treat any potential reactions.
Newer treatments are being explored through research. One of these treatments includes food desensitization, a process by which a child’s immune system is made less reactive to a food, decreasing the likelihood of anaphylaxis (a life-threatening type of allergic reaction) after accidental ingestion of the food in question.
Frequently Asked Questions
About Food Allergy
When should I introduce foods to my baby?
Complementary foods (foods given in addition to breast milk), including rice or oat cereal, vegetables, fruits, and then age-appropriate foods with meats may be introduced between 4 to 6 months of age. Highly allergenic foods, such as cow’s milk, eggs, peanuts, tree nuts, soy, wheat, fish and shellfish, may be introduced after a few complementary foods are tolerated. Although dairy products also may be introduced at this time, whole cow’s milk as the infant’s main drink should be avoided until age 1 for other reasons, including low iron content and the risk of dehydration due to the high electrolyte content of cow’s milk. Whole peanuts and tree nuts carry aspiration risks and should be avoided until the child’s physician feels they are safe.
How should I introduce the highly allergenic foods?
First of all, these foods should be initially given at home, rather than at a daycare or restaurant. As long as there is no apparent reaction, then the foods can be given in gradually increasing amounts. Lastly, one new food should be introduced and given for three to five days in order to monitor for allergic reactions. Parents should note that local skin reactions, including a red rash or hives around the mouth due to irritation from the acid of some fruits (i.e., berries, tomatoes, citrus fruits and vegetables) are not considered a food allergy, so delayed introduction of these foods is not recommended.
As a pregnant or breastfeeding mom, should I avoid any foods? How long should I breastfeed? What kind of formula should I use to help prevent food allergies?
Maternal avoidance diets during pregnancy and lactation are not recommended at this time. Exclusive breastfeeding is recommended for at least 4 months and up to 6 months of age. This has been shown to possibly reduce the incidence of atopic dermatitis in children under age 2, reduce early onset wheezing before age 4, and reduce the incidence of cow’s milk allergy in the first two years. Although no specific formula is recommended over another, hydrolyzed formula appears to offer advantages in preventing allergic disease when given to infants who have increased risk of allergic disease and who cannot be exclusively breastfed for the first four to six months of life.
When should I bring my child in to see the allergist?
When an infant has poorly controlled, moderate-to-severe atopic dermatitis or has a reliable history of an immediate allergic reaction to a certain food, then referral to an allergist is warranted. If a food which has not been introduced yet tests positive in a serologic food-specific serum IgE test, an allergist may help decipher the results and perform a food challenge before prematurely avoiding certain foods. Conversely, if a food tests negative despite a convincing history of an allergic reaction, then an allergist may recommend skin-prick testing and an oral food challenge, instead of having the family try the suspect food at home again. Lastly, a child who has a sibling with a peanut allergy has a 7 percent risk of peanut allergy. Even though the risk of introducing peanuts to these children is low, the physician or parent may request a referral to an allergist before introducing peanuts.
About Benjamin Ho, M.D.
Benjamin Ho, M.D., is a pediatrician with Texas Children’s Pediatrics. His clinical interests are asthma and preventive health. Dr. Ho attended Brown University and graduated from The University of Texas Medical School at Houston. He completed his residency and internship at Baylor College of Medicine. Dr. Ho was the recipient of a Patients’ Choice Award from Vitals.com from 2007–2011. He is an American Academy of Pediatrics fellow and a member of the American Medical Association, American Academy of Pediatrics and Texas Medical Association. He and his wife have two boys.