The fear about peanut allergies is nuts

Parents and medical groups are doing more harm than good stirring up worries about food allergies.

Published February 5, 2009 11:38AM (EST)

In 2005, a 15-year old Canadian teenager named Christina Desforges kissed her boyfriend and died. Her death, reported around the world, was initially blamed on peanuts. Desforges was allergic to peanuts and her boyfriend had eaten peanut-butter toast hours before their deadly smooch.

Sudden death due to an allergic reaction to food is known as anaphylaxis. When you eat peanuts (or some offending food), you break out in hives, your face swells and your larynx constricts until you can no longer breathe, all in a matter of minutes. Shocking. Tragic. Scary.

Desforges' story is the kind that has moved anxious parents, politicians and school board members to join a crusade against peanuts. Several states have passed laws mandating public schools be "peanut-free zones," and parents now hover over food labels with Draconian vigilance, checking and double-checking them for signs of peanuts. Could that knife that just cut the birthday cake have been in the vicinity of peanut butter?

Peanut-allergy panic has spread across the nation. In a recent essay, Harvard physician and sociologist Nicholas Christakis relates an incident in which a peanut was spotted on the floor of a school bus, "whereupon the bus was evacuated and cleaned (I am tempted to say decontaminated), even though it was full of 10 year olds who, unlike 2 year olds, could actually be told not to eat off the floor."

Actions like that are no doubt overdue in the minds of organizations like the 30,000-member Food Allergy and Anaphylaxis Network (FAAN), a Virginia-based advocacy organization that has led the fight to raise awareness about peanut and other food allergies in both children and adults. Go to its Web site and you'll see some eyebrow-raising points.

• The incidence of food allergies has doubled over the past 10 years.

• Food allergy is believed to be the leading cause of anaphylaxis outside hospitals, causing an estimated 50,000 emergency department visits each year in the U.S.

• Each year in the U.S., it is estimated that anaphylaxis caused by food results in 150 deaths.

Those FAAN numbers get cited in nearly every news report about food allergies. The organization's founder, Anne Munoz-Furlong, mother of a food-allergic child, is well known in the media as a food allergy expert. She has done her own research and her studies have been published in medical literature. Now major medical groups, like the American Academy of Pediatrics, have recommended that children avoid eating peanuts until age 3. As for consuming other potentially allergic foods (such as strawberries or dairy), the AAP has, until recently, suggested that kids wait until age 2.

But on closer examination, food allergies are not the epidemic we've been led to believe. FAAN's advocacy may have helped to create rules and laws that are based less on sound science than on a significant misrepresentation of facts. Ironically, by accepting these facts, we may be increasing our risk of developing food allergies.

Consider the claim that food allergies have doubled. FAAN states it drew this conclusion in part from doctors' "reports" (that is, anecdotes and not hard data about confirmed allergies). FAAN's claim is also based on a study looking at the prevalence of peanut and tree nut allergies. In that study, funded in part by FAAN, researchers, one of whom was Munoz-Furlong, obtained data by conducting a telephone survey, in which they asked questions about whether someone at home has a nut allergy.

Besides the problem that FAAN took information about a specific type of food allergy and applied it to all food allergies, telephone surveys are notoriously inaccurate. They're subject to recall bias: People have to pull events out of imperfect memories.

There's also good evidence that parents overestimate the prevalence of food allergies in their kids. In one 2005 study, parents reported that 7 percent of kids under age 3, 10 percent who were age 3, and 8 percent over 3 had food allergies. But when researchers tested those kids to confirm these self-reported diagnoses, there were no confirmed cases under 3, only 2 percent at age 3, and 1 percent over age 3. Other studies have shown similarly large discrepancies between what parents believe about food allergies and what tests confirm.

Further, what constitutes a peanut allergy for a parent is not what constitutes it for a doctor. If a child has diarrhea or vomits after eating nuts, it may signal a food allergy, but it may also mean food poisoning. The FAAN study did not confirm its subjects' claims that they were allergic to nuts. That would have required medical records and testing, neither of which were included in the study. Valid confirmation depends on a blood or skin test. Potential allergens are placed on or just underneath the skin to see if they trigger a localized allergic response. Although even those tests can be unreliable, as they don't always pinpoint which food may or may not be the problem.

Let's look at FAAN's claims that 50,000 people a year end up in emergency rooms with allergic reactions and that between 150 to 200 people die each year from anaphylactic shock. That 50,000 is extrapolated from a study in which researchers looked at emergency room visits, due to anaphylaxis, in a single hospital over 10 years. The number of visits during one year was actually 211. The researchers then estimated that 211 people from one E.R. adds up to 50,000 people across the country. Whether that's true remains to be seen. There's no evidence that visits in one hospital correspond to visits in hospitals across the country.

What's also misleading is how FAAN couches this information in its press kit: "Food allergy is believed to be the leading cause of anaphylaxis outside the hospital setting, causing an estimated 50,000 emergency department visits each year in the U.S." In fact, the study is citing any cause of anaphylaxis. FAAN suggests that 50,000 people visit an E.R. due solely to anaphylaxis from food allergies. That's simply not true.

The claim that 150 to 200 people die each year from anaphylaxis is grossly exaggerated. In 2004, the Centers for Disease Control cited just 14 deaths due to anaphylaxis. The only known registry of deaths from anaphylaxis noted 33 deaths between 1994 and 1999. Remember, all of these estimates refer to the total number of people who had an anaphylactic reaction for any reason, not just from peanuts or other foods.

Facts ought to be stubborn. In the past, Munoz-Furlong has stated that one child dying from an allergic reaction is too many. But Harvard doctor Christakis, again, puts things into perspective. "There are no doubt thousands of parents who rid their cupboards of peanut butter but not of guns," he writes, comparing the alleged 150 children and adults who died from peanut allergies to the 1,300 who die from gun accidents each year. He goes on to note that 2,000 kids drown each year. Indeed, the most common cause of death in kids is accidents. "More children assuredly die walking or being driven to school each year than die from nut allergies," Christakis writes.

The worst fallout is that doctors and medical groups who have fallen for the FAAN hype are doing more harm than good with their prescriptions to avoid peanuts. A study published last year compared the prevalence of peanut allergies in Jewish children in the United Kingdom (where young kids are told to avoid peanuts) with those in Israel (where peanuts are fine).

Unlike the survey-based studies before it, researchers administered two strictly validated questionnaires to identify kids with allergies. Then those kids were tested. In all, about 5,000 kids were included in each group. The result: Less than 2 percent of U.K. children were allergic to peanuts, compared to a mere 0.17 percent of Israeli children. The authors concluded: "Paradoxically [avoidance of peanuts] might be promoting the development of peanut allergies and could explain the continued increase in the prevalence of peanut allergies."

For those who argue that heightened awareness about food allergies is more beneficial than underestimating them, consider the psyche of kids who fear they have an allergy. They often wear a bracelet or necklace identifying them as food allergic and carry injectable epinephrine wherever they go. While those measures are justified for truly allergic kids, what about those who may not be? Research has shown these children report feeling more anxious, restrict their activity and are more worried about being away from home than even children with Type 1 diabetes.

The mismatch between the fears and the facts is beginning to surface. Recently the American Academy of Pediatrics reconsidered its policy of preaching avoidance. In a statement, it declared: "It is evident that inadequate study design and/or a paucity of data currently limit the ability to draw firm conclusions about certain aspects of [allergy] prevention through dietary interventions." In addition, a new international and comprehensive study is now under way to uncover solid data about the true incidence and prevalence of food allergies.

And what about Christina Desforges, the young girl who received the kiss from the peanut-contaminated lips of her boyfriend? She suffered from asthma and died of a severe asthma attack, likely triggered by smoke. A coroner reported that on the night she collapsed she had smoked marijuana and spent hours at a party where people were smoking pot and tobacco.

- - - - - - - - - - - -

Read FAAN's response

By Rahul K. Parikh

Rahul K. Parikh is a physician and writer in the San Francisco Bay Area. He wrote the Vital Signs column on Salon in 2008-2009. His pop culture-medical column, PopRx, runs on alternate Mondays.

MORE FROM Rahul K. Parikh

Related Topics ------------------------------------------

Food Allergy Health Medicine Vital Signs