Researchers say that food allergies have increased by about 50% in the past decade. What’s causing the surge and can you do anything to protect your children?
Most people know the foods that often cause allergic reactions—peanuts, milk, shellfish, and wheat are the most common culprits. But the prevalence of these and other food allergies is growing faster each year. Pediatricians and immunologists at Mount Sinai School of Medicine in New York City are researching why. Although there is no confirmed data showing that allergies are becoming more prevalent, 6% to 8% of all children younger than 4 years old have some type of food allergy. The National Institute of Allergy and Infectious Diseases advises that toddlers and infants are the most vulnerable. Even though only about 1% of children have a peanut allergy, there are more than 100 deaths each year in the United States from reactions to food allergies, and most of those are allergies to peanuts.
Although any food can trigger an allergic reaction, the most common ones in the United States are caused by wheat, milk, eggs, peanuts and other nuts, soybeans, fish, and shellfish. Another food allergy that is on the rise among children is allergy to sesame and other seeds and seed oils. Although most children with these allergies are diagnosed because of a sudden reaction to ingesting the oil, many have symptoms that aren’t very dramatic, so their parents and physicians may not recognize them as being a food allergy. The rise in sesame allergy cases is probably due to the increasing popularity and production of foods containing sesame seeds.
In addition to researchers not knowing why food allergies on the rise, there is also confusion about what can be done to prevent them. Doctors have told parents for years that if they have allergies themselves, they should avoid feeding their children the foods known to be related to allergies—eggs, peanuts, fish, and nuts—but the American Academy of Pediatricians now believes that there may be no merit in this advice. In the United States, foods made with peanuts are usually produced using roasted peanuts, and this is probably why those foods are more allergenic. In countries where peanuts are boiled before processing, there is a much lower prevalence of peanut allergies.
Food allergies aren’t the only allergies that are becoming more prevalent. In the last two decades there has been a significant increase in asthma, hayfever, and eczema. The percentage of Americans who test positive to at least one allergen has doubled since 1980, and asthma rates in infants and children have tripled. Many researchers and doctors believe this is due to what they call "the Hygiene Hypothesis." Nowadays there is so much emphasis on hygiene and anti-bacterial soaps, lotions, detergents, cleaners, and dishwashing soap, that many children have improperly developed immune system because they haven’t been exposed to the dirt and bacteria that would help them build up antibodies and resistance to diseases. Because the immune system doesn’t have as many natural germs to fight, it overreacts to other foreign substances (such as nuts, pollen, and dust) that aren’t dangerous to the human body.
If a child has an allergy to a certain food, he most likely will not exhibit symptoms the first time he is exposed to the food. But his immune system will begin producing antibodies that will help fight what the body perceives as a foreign invader. This can even happen during breastfeeding, because part of everything eaten by the mother is passed on to the baby through breast milk. Then when the child eats that food later, those antibodies will release chemicals to cause an allergic reaction.
Symptoms of a food allergy can include itching, flushed skin, hives, diarrhea, vomiting, swelling, watery eyes, sneezing, a runny nose, and a wheezing cough. In some rare cases, a food allergy results in a life-threatening swelling of the airways, where the blood pressure drops and breathing becomes difficult or impossible. This reaction is called anaphylaxis, and medical attention should be sought immediately.
Since there is such a wide array of symptoms that can be exhibited when a food allergy is triggered, it is sometimes difficult to know whether the symptoms indicate an allergic reaction to food, or something more serious or benign. The key to knowing the difference is usually the timing of the occurrence of symptoms. With a food allergy, symptoms almost always appear within just a few seconds or a few minutes after eating the offending food. Most children who have food allergies will have a skin reaction such as hives or flushed skin within just a few minutes after eating. If you suspect that your child may have a food allergy, it is important to get an appointment with a pediatric allergist. This doctor will get a thorough history detailing your child’s sensitivities to various foods, and then use blood tests or skin tests to determine whether your child has any food allergy antibodies.
If your child eats something and has even a mild reactive symptom, it’s important to pay attention to that and call your pediatrician for advice. Just because your child has a mild reaction the first time doesn’t ensure that the next reaction will also be a mild one. When it comes to food allergies, it’s better to be safe than sorry.
