Food Allergies on the Rise
Food allergies are on the rise in developed countries, and researchers are trying to discover why. According to a 2013 study by the Centers for Disease Control and Prevention, food allergies among children increased by about 50 percent between 1997 and 2011.
There’s a good chance you know — or even parent — a child who has a food allergy. Dr. Ceyhun Ozturk of Little Oaks Pediatrics in Raleigh says "one in 13 children in the United States is affected by food allergies." The prevalence of peanut allergies among children, for example, more than tripled from .4 percent to 1.4 percent between 1997 and 2008, according to a 2010 study conducted by the American College of Allergy, Asthma and Immunology.
Why are these increases occurring? Understanding the possible causes has stumped many experts.
Hypotheses
Allergy and immunology experts are unable to offer an exact cause for the increase in allergies, but have formed a few hypotheses. According to the UCLA Food and Drug Allergy Care Center, the "hygiene hypothesis" states that excessive cleanliness interrupts the normal development of the immune system, which can lead to an increase in allergies.
"In short, our ‘developed’ lifestyles have eliminated the natural variation in the types and quantity of germs our immune systems need for it to develop into a less allergic, better regulated state of being," the UCLA Food and Drug Allergy Care Center website states.
Another hypothesis published in 2006 by the Adverse Reactions to Foods Committee at the American College of Allergy, Asthma and Immunology, suggests that a child’s risk of developing a food allergy is greater when the child is fed solid foods before 6 months of age. The Mayo Clinic, however, challenges this view, asserting on its Infant and Toddler Health Web page that "postponing solids — including highly allergenic foods — past 4 to 6 months of age also hasn’t been shown to prevent asthma, hay fever, eczema or food allergies."
Another recent study concluded that early introduction of foods with peanuts may decrease the development of a peanut allergy. The study conducted at King’s College in London, included more than 600 infants ranging in age from 4 to 11 months. The study indicated that for every 100 children, 14 would normally go on to develop an allergy by the age of 5. For children who were introduced to foods with peanuts as infants, that number fell by 86 percent, to just two out of every 100 children. Doctors and researchers are hopeful that with new evidence and more research that early introduction of foods can help curb other food allergies, and that new protocols will follow, but warn not to experiment at home.
Identification
The first step to solving this mystery is to understand what is going on during an allergic reaction.
"Food allergy basically occurs when your immune system inappropriately forms allergic antibodies to foods someone has been exposed to during their life," says Dr. Joel Hartman of Allergy Partners of the Piedmont.
This struggle usually arises during a child’s first and second year of life and often manifests as an allergy to milk, eggs, peanuts, tree nuts, wheat, soy, fish and/or shellfish.
"Milk is tough, especially if kids are reactive to milk in baked goods, so families have to be diligent about label-reading, because milk, soy, wheat and egg can be hidden in a lot of foods," says Dr. Emily Langley of Carolina Asthma and Allergy, which has locations throughout the Charlotte area.
Parents of allergic children should ask questions at restaurants if they are unclear on what entrees contain, and should keep an eye on their allergic child if he or she does eat something he or she is allergic to, since the reaction may not appear immediately. "Typically food allergy presents within 20 to 30 minutes if not immediately after you eat a food, and a kid will develop hives or a rash around [his] face, chest or all over his body; may experience swelling of the lips or tongue; may start coughing, wheezing, having difficulty breathing; or have nausea, vomiting and diarrhea," Langley says.
Identification is not always straightforward. "It can overlap with a lot of other conditions like food sensitivities, gastrointestinal illnesses, viral illnesses or food intolerances, so it can be difficult to discern if it is an allergy or another medical illness going on," Langley adds.
Confirmation
To confirm a food allergy, see a doctor. "We take history and decide the best way to test, but the only absolute way to make certain you do not have a food allergy is for the allergist to perform what is called an open food challenge in the office, where the patient brings the food to the office and over a period of an hour or two we introduce small amounts, increasing [the amount] over that time," Hartman says. This helps rule allergies out.
Based on the clinical reaction, doctors may choose to run a skin test, which involves pricking the skin with an extract of the allergenic protein and looking for what is called a "wheel and flare response," which is the appearance of a small hive or mosquito bite at the site of the skin prick, Langley says. Or, doctors may choose to run a blood test called a RAST (radioallergosorbent test), she says, which helps identify allergy antibodies to a certain food.
Guidelines
Ozturk says in 2000, the American Academy of Pediatrics advised delaying the introduction of highly allergenic foods to high-risk infants. This meant delaying the introduction of cow’s milk until age 1; egg until age 2; and fish, peanuts and tree nuts until age 3.
More recent guidelines are less stringent but still unspecific.
"[The AAP] determined in 2008 that there was no convincing evidence for delaying the introduction of highly allergenic foods, but the report did not provide guidelines on how and when to introduce them, so it is still a highly debated topic among pediatricians and allergists," Ozturk says. "The medical community is split on the issues, but there are good proponents to delay allergenic foods, but also proponents for introducing them as early as 4 to 6 months — except cow’s milk because consuming high amounts of cow’s milk before 12 months makes you run the risk of developing low hemoglobin or anemia."
Some factors are out of parental control. "Kids most at risk have a family history like a parent or sibling with an allergic condition — whether it is asthma, food allergy, eczema or environmental allergies," Langley says.
Nobody said managing food allergies would be easy.
"It is a life-threatening condition and also a change in lifestyle for an entire family," Langley says.
Treatment
In an effort to treat food allergies, several universities across the U.S. are performing desensitization clinical trials.
A clinical trial being conducted at Stanford University combines a shot of the drug Xolair with slowly increasing exposure to the foods that a patient is sensitive to. So far, 700 participants in the clinical trials have developed the ability to eat foods that previously triggered an allergic reaction. The treatment begins with a series of injections to lower the patient’s immune response. Slow and low exposure to the allergen follows and then researchers increase the "dose" of the allergy-causing food over the course of up to a year.
"I am hopeful that over the next decade that we may have something to offer families other than just avoidance and treatment of acute situations," Langley says.
Jamie Lober, author of Pink Power, has a passion for health promotion and disease prevention. She can be reached at jamie@getpinkpower.com.
SIDEBAR
Tips for Treating Allergic Reactions
1. Be prepared.
For severe allergic reactions, an epinephrine injection may be necessary. "It is important to seek emergency care and call 911 after you inject epinephrine, because you may feel better, but once the medication gets out of your system you may experience subsequent reactions and should be observed for 4 to 5 hours and monitored closely with vital signs," says Dr. Ceyhun Ozturk of Little Oaks Pediatrics in Raleigh.
2. Educate.
Help the people who help take care of your child read labels and understand your child’s routine. "The Food and Drug Administration back in 2004 passed an act that required all packaged foods with few exceptions to list the common allergens that may be contained in the food that is being sold," says Dr. Joel Hartman of Allergy Partners of the Piedmont. "This was helpful."
3. Treat appropriately.
"If a child develops hives only, it would be safe to administer an appropriate dose of Benadryl, monitor him and call the primary care doctor," says Dr. Emily Langley of Carolina Asthma and Allergy, which has locations throughout the Charlotte area. "But if symptoms are more severe — like the child is breathing hard or fast, vomiting or you perceive the throat is getting tight — you should call 911 immediately."
4. Track growth.
"In the process of eliminating allergens, parents are sometimes overly careful and there could be nutritional deficiencies, so we have to keep a close eye on the growth chart to make sure height and weight are normal for their age," Ozturk says.
