Allergy Tests and Food Diets: What Parents Need To Know

By Bara Vaida
WebMD Health News

Reviewed by Hansa D. Bhargava, MD

Angela Moore's pediatrician was on the phone, relaying some frightening news about her 8-year-old son.

Dennis' blood test results showed he was allergic to corn, wheat, watermelon, and all tree nuts.

"I was totally freaked out," says Moore, who lives in suburban Atlanta. "I was so scared that he would stop breathing if he ate the wrong thing."

Moore ran to her local pharmacy and bought three packages of EpiPens, which treat severe and life-threatening allergic reactions. She also removed the red-flag foods from Dennis' diet. Still, Moore was puzzled by the test results. Dennis had seasonal allergies, but he'd never reacted to food, except watermelon, which caused his lips to swell. A week earlier he had eaten a peanut butter sandwich without a problem.

A few months after this happened last May, Moore sought a second opinion with pediatric allergist Luqman Seidu, MD. He's the head of Omni Allergy, Immunology and Asthma in Atlanta.

After checking the child's blood results and learning his medical history, Seidu told Moore that Dennis wasn't allergic to anything.

Relieved, Moore has since let her son have corn, wheat, and nuts. "Had I not had that mother's intuition that I needed some better answers, I would have been totally changing his diet, and I would have been paranoid about everything that he was putting his mouth," she says.

'Nutritional Consequences'

With the rise in food allergies over the past decade, allergists trained to treat children say they are seeing more cases where kids are being wrongly advised by pediatricians and primary care doctors to stop eating certain foods.

In November 2014, a task force of the nation's allergists repeated that doctors should not use lab tests alone to diagnose food allergies. It also strongly recommended that doctors tell parents to speak with a nutritionist if they're considering a food elimination diet for their child.

Doctors "must be aware of the nutritional consequences of elimination diets and certain medications ... in growing children," the group said.

"Every day I see a parent of kids who have been misdiagnosed with a food allergy," says Seidu. Food allergy test results need to be looked at along with a child's medical history. Also, Seidu says blood tests can be misleading. "My blood test says I'm allergic to peanuts and hazelnuts. But I'm not," he says.

Pediatric allergists also say that more parents have removed foods from their children's diet because they feel that their child has a food sensitivity. That generally means an unpleasant reaction to certain foods.

"There is a big increase in parents coming in who have put their kids on the elimination diets and they want to know if I agree if it is the right thing," says Robert Wood, MD. He's a professor of pediatrics and the division chief of allergy and immunology at The Johns Hopkins Hospital in Baltimore. "Usually food isn't the problem."

He says parents are most often cutting out dairy and gluten, a protein in wheat. "The foods that we are talking about [with elimination diets] are important sources of nutrition."

Poor nutrition "is potentially very dangerous," because it can lead to a failure of a child to thrive, says Erwin Gelfand, MD. He's the chair of pediatrics at National Jewish Health, a hospital in Denver that specializes in treating allergies. In April 2011, a doctor there published a study in the Journal of Pediatrics showing that 84% to 93% of foods that had been needlessly eliminated from a group of children's diets could be returned.

Children who don't eat or drink dairy products might miss important sources of vitamin D and calcium needed for bone and immune system health, says Michelle Henry, MPH. She's a clinical, registered dietician at the Digestive Health Institute at Children's Hospital Colorado in Denver. Without wheat and foods with gluten, children could miss out on folic acid that's needed for heart health, and iron needed to create red blood cells, Henry says.

Is It a Food Allergy or Something Else?

Data on just how many children have an allergy vary. The Milwaukee-based physicians' group American Academy of Allergy, Asthma & Immunology (AAAAI) says that in 2010, about 8% of children under the age of 18 were allergic to one or more foods -- the most common were allergies to peanuts or cow's milk. The number is larger when parents themselves were asked if their children had a food allergy.

Part of the problem is that parents are confused about food allergies, food intolerance, celiac disease, and food sensitivity, says Mark Holbreich, MD. He's an allergist with Allergy and Asthma Consultants in Indianapolis.

An allergic reaction is an abnormal immune-system response. It creates proteins in blood called immunoglobulin E (IgE) antibodies. It has specific symptoms that happen within minutes or hours. They may include itching, hives, eczema, trouble breathing, vomiting, stomach pain, and diarrhea. In severe cases, an allergic reaction can lead to anaphylactic shock, a sharp drop in blood pressure that can cause a person to stop breathing and can affect the heart.

To know for certain if a child has an allergy, doctors take a history of a child's reactions to certain foods, along with blood and skin tests. Then they do a controlled food challenge under medical supervision. During the challenge, doctors give patients a tiny portion of food to eat and assess their response.

A person with a food intolerance or sensitivity is missing an enzyme that lets their body process the food correctly. Food intolerance can result in bloating, diarrhea, and gas. It can be detected by a blood test.

With celiac disease, gluten causes the immune system to attack the lining of the intestine, making the person sick. About 1% of the population is thought to have celiac disease. The condition is confirmed through blood work and an intestinal biopsy.

Unlike an allergic reaction, food sensitivity doesn't involve an immune system response. Scientists are still trying to understand the cause of the latter, making it hard to test. The immune system makes another type of antibody, called immunoglobulin G (IgG), which some laboratories claim indicates food sensitivity.

Some of the tests are marketed directly to consumers and can costs in the hundreds of dollars. But allergists caution the tests give people too many "false positive" results, which incorrectly point to a food sensitivity, to be reliable. A study involving 21,305 adults published in January 2013 in PLoS One found no evidence that an IgG antibody test indicates a food sensitivity.

The "IgG [test] is unproven," says Scott Sicherer, MD. He's a professor of pediatrics, allergy, and immunology at the Jaffe Food Allergy Institute at the Icahn School of Medicine at Mount Sinai in New York City. The 2014 Joint Task Force update also said that doctors should not order IgG tests to determine food allergies or food sensitivities.

Despite the lack of evidence, doctors like Alessio Fasano, MD, believe one of the chief reasons why food sensitivity tests and food elimination diets remain popular among parents is the "placebo effect."

"They [parents] are doing something that they really feel can have an impact" and therefore it does, says Fasano. He's the chief of pediatric gastroenterology and nutrition at MassGeneral Hospital for Children. For others, an elimination results in better eating habits, which in turn can lead to someone feeling better. He says it may also be that for some people, certain foods really are an irritant to their system and removing them is helpful.

Two Mothers' Stories

Kami Hadley's daughter Addyson lagged in weight and body growth beginning at about 2. A pediatrician sent Addyson to an allergist, who determined that she was allergic to eggs, soy, corn, and peanuts -- so Hadley removed them all from her daughter's diet. Hadley worked with a nutritionist, but Addyson failed to grow -- by age 4 she weighed just 24 pounds.

In June 2014, Hadley took Addyson to Denver's National Jewish Health, which has a program for children allergic to multiple foods. There Addyson took a series of food challenges showing she was allergic to coconut, peanuts, tree and sunflower nuts, but not to wheat, peas, chickpeas, soy, and corn. Those foods could all be returned to her diet. Addyson, now 5, is and eating and gaining weight, Hadley says.

Many parents with children who have autism, attention deficit disorder, or other medical problems such as persistent ear and sinus infections have tried cutting out dairy, sugar, and wheat from their children's diets. They feel that their child is sensitive to those foods, or they're desperate to try something.

Lauren Fox, a mother of three who lives in the suburbs of San Francisco, was one of those distressed parents. Her son Caleb had severe ADD and couldn't sit still in school. He also had trouble making friends. In 2013, Fox sought out the help of Sanford Newmark, MD, head of the pediatric integrative neurodevelopment program at the Osher Center for Integrative Medicine at the University of California, San Francisco.

He suggested that she get rid of dairy, eggs, food coloring, gluten, nuts, and sugar from Caleb's diet, and then slowly add them back to figure out which food had an impact on his behavior. To her surprise, Caleb's behavior improved. The two foods that seemed to cause the most problems were gluten and sugar. Caleb, now 10, eats neither.

"It has proven amazing," says Fox of the diet. "His teachers tell me that they don't see any of the ADHD behavior."

Questions Remain

But the majority of doctors remain skeptical of stories like Fox's, because no large and scientifically rigorous research studies have been able to duplicate such responses. One smaller study of 67 people found that a gluten-free diet improved symptoms in people with ADHD.

Scientists have done decades' worth of research on the connection between autism and gluten. The research has yielded similarly uncertain results. A recent look at 35 years of studies considering the link between autism and gluten remains "limited and weak," according the April 2014 issue of the Journal of Child Neurology.

Also, the FDA looked at studies on artificial food coloring in 2011 and determined there wasn't enough evidence that it caused ADHD. Based on the evidence, the allergists' task force said doctors shouldn't advise parents to avoid food additives as a treatment for ADHD.

Scientists have also looked into the connections between sugar and behavior. An analysis of 16 studies found sugar had no impact on behavior and thinking skills, according to a November 1995 study published in the Journal of the American Medical Association.

On the other hand, at least one large analysis of 34 studies found artificial food colors had a small but significant effect on ADHD symptoms, according to the January 2012 issue of the Journal of the American Academy of Child and Adolescent Psychiatry.

Erika Melchiorre, a mother of two who lives in Summit, N.J., is a medical professional. She believes the science will eventually prove parents right. The optometrist says she put her son Jack on a gluten-free diet when he was 3 after he was diagnosed with a sensory processing disorder that made him unable to sit still or follow directions.

"We tried occupational therapy and speech therapy, and that helped some, but not as much as taking him off gluten," Melchiorre says. "After 4 to 6 weeks, he was much more in control and could focus. I just think the research will get there. It's naive to think what we put in our bodies doesn't have an impact."


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SOURCES: Luqman Seidu, MD, pediatric allergiest, Omni Allergy, Atlanta. Robert Wood, MD, professor of pediatrics, division chief of allergy and immunology, The Johns Hopkins Hospital, Baltimore. Michelle Henry, MPH, registered dietician, Digestive Health Institute at Children's Hospital Colorado, Denver. Mark Holbreich, MD, allergist, Allergy and Asthma Consultants, Indianapolis. Sicherer, MD, professor of pediatrics, allergy and immunology, Jaffe Food Allergy Institute, Icahn School of Medicine at Mount Sinai, New York City. American College of Allergy, Asthma & Immunology. Alessio Fasano, MD, chief of pediatric gastroenterology and nutrition, Director of the Center for Celiac Research, MassGeneral Hospital for Children. Laura Fox, mother, San Francisco. Sanford Newmark, MD, Head of Pediatric Integrative Neurodevelopmental Program, Osher Center for Integrative Medicine, University of California, San Francisco. Pediatrics. Celiac Central. National Jewish Health. BetterHealth USA. Medscape. FDA Erika Melchiorre, mother, Summit, N.J. Niderhofer, H. The Primary Care Companion for CNS Disorders, 2011. Fleischer, D. The Journal of Pediatrics, April 2011. Zeng, Q. PloS One, Jan. 3, 2013. Naru-Bauset, S. Journal of Child Neurology, Dec. 29, 2014 Wolraich, ML. Journal of the American Medical Association, Nov. 22-29, 1995. Nigg, J. Child & Adolescent Psychiatry, January 2012. Joint Task Force on Practice Parameters.

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