Add food allergies to the growing list of childhood ailments on the rise. The Centers for Disease Control & Prevention recently reported that some 3 million American children are allergic to some type of food, a whopping 18 percent increase over the past 10 years. And it’s not just in the U.S.; childhood food allergy rates are skyrocketing throughout the developed world. Dr. Christina Schwindt, a pediatrics professor with a specialty in allergies and immunology, leads UCI’s effort to understand why this is happening and to treat children who suffer from food-based allergies.
Q: How do food allergies affect children?
A: A food allergy is an immune system response to a food that the body mistakenly believes is harmful. Once the immune system decides a particular food is harmful, it will release massive amounts of chemicals to protect the body each time that food is eaten. These chemicals trigger a cascade of allergic symptoms that can affect the respiratory system, gastrointestinal tract, skin and cardiovascular system. Common allergic reactions in children range from a tingling or itching mouth to body swelling, hives, and more severe reactions such as difficulty breathing, loss of consciousness and even death.
Q: Which foods trigger the most reactions?
A: Although an individual could be allergic to any food, such as fruits, vegetables and meats, there are eight foods that account for 90 percent of all allergic reactions – milk, eggs, soy, wheat, peanuts, tree nuts, fish and shellfish. These foods are particularly allergenic because they contain protein structures that stimulate the immune response and consist of stable molecules resistant to processing, cooking and digestion.
Q: Why are more kids allergic now than before, and why are rates growing around the world?
A: Currently, we do not understand why there is an increase in food allergies or other allergic disorders that occur globally in both developed and developing countries. We do know that genetics are involved, but the speed of increase is too fast to be genetics alone. It suggests a gene-environment interaction that occurs when there are environmental changes such as air pollution, hygiene, exercise or diet.
Q: What research is being done to identify these possible environmental factors? Are you involved with any?
A: Identifying environmental and lifestyle factors involved in allergic disease is a hot research topic around the world, and modifying these factors holds promise for stopping allergic disease in the future. At UCI, we’re also very interested in this topic. We’re investigating whether exercise can be used as a prescription to modify existing allergic diseases – in particular, exercise-induced asthma and anaphylaxis associated with food ingestion – and whether exercise in young children can modify the development of allergic disease.
Q: Is a child who is allergic to one food more likely to have allergies to others?
A: Multiple food allergies can occur and often are associated with eczema and other allergic diseases. There is a high rate of false positive results with commonly used skin and blood test methods, so it is important to be evaluated by a medical specialist to determine the presence of food allergies. They may want to perform a food challenge or elimination diet to confirm suspected food allergies.
Q: Can food allergies be cured?
A: There is no cure for food allergies, but there is treatment that begins with early recognition and management of the food that causes the reaction. For severe reactions, injectable epinephrine is the medication of choice. Trained medical specialists can help you identify food allergies, develop a treatment plan and provide advice on significant dietary changes to ensure that removing a food from your diet does not create other health problems.
Q: What preventative steps can be taken?
A: Strategies have been developed to identify and hopefully prevent food allergies and other allergic diseases in babies. Infants considered at risk are those with a family history of food allergies or early evidence of allergic disease or sensitization. Prevention strategies include exclusive breast-feeding for at least four months or, if necessary, supplementing with hydrolyzed formula (in which proteins are broken down into smaller parts that may not be recognized by the body as allergenic).
Interestingly, there is little evidence suggesting that maternal dietary restrictions during pregnancy and lactation prevent food allergies, and there is no need for any dietary restrictions beyond four to six months of age.
Q: Do children grow out of their food allergies?
A: Yes. Many people outgrow their food allergies, although peanuts, tree nuts, fish and shellfish are often considered lifelong allergies.