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Food Allergies: Facts, Myths, and Pseudoscience

The price of life is eternal vigilance. If you have severe food allergies, that is your reality. Every day, every meal, every bite. Eating is an intrinsic and essential part of what we do and who we are, so the idea that our bodies can rebel violently to everyday foods can be difficult to believe. But it’s real, and the numbers of the severely food allergic are growing. Frustratingly, we don’t know why. While recognized over 100 years ago, the social acknowledgment had lagged. That’s improved in the past decade. Food allergy prevention approaches are now a routine part of travel, school, sports, and the workplace. Peanuts on planes seem to have completely disappeared. The days of lunchbox peanut butter sandwiches are over, with many schools completely banning all peanut-containing products. It is the education system that seems to have become a ground zero for allergy programs and policies, where educators are challenged to ensure that schools are safe environments for all children, some of whom have long lists of food allergies.

While 30% of the population believes that they have a food allergy, the actual prevalence is about 5%. Allergies are a product of our immune systems, with multiple biochemical pathways triggered in response to a specific antigen. “Allergy” can describe mild skin reactions and respiratory distress, right through to life-threatening reactions. The majority of food-related allergic reactions are not life-threatening. Anaphylaxis is the term that describes the most rapid and severe immune response, which can occur in response to a drug (the most common cause of anaphylaxis), an insect, or food. Food-allergy anaphylaxis is rare, occurring in one to 70 per 100,000 of the population. Eight food cause over 90% of anaphylactic reactions: milk, eggs, peanuts, tree nuts, fish, shellfish, soy, and wheat. Reactions may involve multiple body systems (gastrointestinal, skin, respiratory) including breathing difficulties and swelling of the throat. Anaphylaxis is estimate to have fatality rates of 0.7-2%. Death occurs due to upper airway obstruction, vascular fluid shifts, and depressed heart function. The risk of anaphylaxis, and how quickly it can appear in any individual with a history of allergy, is difficult to predict, and can be influenced by age, the type of allergen, the extent of exposure, and underlying illness like asthma.

Evaluation of anaphylactic food allergies involves a number of diagnostic tools including skin testing, in-vitro tests, and food challenges. There is no single diagnostic test. Different tests may be used depending on the patient’s history of reactions. All of these tests have different risks and benefits and must be performed under the supervision of an allergist, where immediate access to resuscitation equipment is available. Food allergies in children can resolve over time, like milk and egg. Tree nut and peanut allergies, however, are more likely be life-long conditions.

Given the life-threatening nature of some food allergies, you’d think there would be no room for myths or pseudoscience. You’d be wrong. Confusion and misinformation abounds. There is the unfortunate tendency to label any sort of negative reaction to any substance as being an “allergy”. I see this frequently when speaking with patients about their medical history, who rhyme off a long list of drug “allergies”, which more frequently describe intolerance, like diarrhea to antibiotics, or nausea and drowsiness from narcotics. Then there are “allergies” pulled out of thin air. The current fad food “allergy” is gluten, a self-diagnosed condition in which gluten is believed to be some sort of dietary toxin – which must be distinguished from (1) the person with the documented anaphylactic wheat allergy and (2) those with celiac disease, an auto-immune response to gluten that requires absolute avoidance (but does not cause anaphylaxis if ingested). Capitalizing on the confusion about allergies and intolerances are alternative medicine providers, who offer their own definitions of allergies, and (conveniently) their own cures. The result is widespread confusion about allergies, and worries that we’re seeing too many nonexistent allergies while raising the risk we’ll miss the truly life-threatening ones. As a parent of young children, I sympathize with the staff at my local school, where each year means a new group of parents who grumble about the school’s policies in place to minimize the risk of allergic reactions. Eggs, peanuts and milk are the most common allergies, but peanuts and tree nuts cause more fatal anaphylactic reactions, so restrictions on those food products are more common. Tragic deaths have driven systems to implement new policies. What’s worse, severe reactions are more common in children and children and young adults are at greater risk of a fatal reaction.

With food allergies, the consequences of a single wrong decision can be fatal. I was reminded of this when I heard about Natalie Giorgi, a 13-year-old girl who died of anaphylaxis this past July after accidentally biting a peanut butter-contaminated Rice Krispie square. Here parents were present and they immediately gave her an antihistamine, diphenhydramine (Benadryl). She initially showed no signs of a reaction. Suddenly she started vomiting, which quickly progressed to a massive anaphylactic reaction. Her father, a physician, administered the two epinephrine injections (Epi-pens) they had on hand, with no effect. A third Epi-pen was found, and given. No effect. Sadly, she could not be resuscitated, even after EMS arrived. Her last words were “I’m sorry, Mom,” and she died in front of her parents. From dancing to dead, in minutes, simply because of a bite of food.

This type of scenario is terrifying to those with allergies, parents, and health professionals. Was this tragedy preventable? Based on the limited information in the story, the only possible error may have been the administration of Benadryl, which may have delayed the first dose of epinephrine. With food-related anaphylaxis fatalities, the median time to death is 30 minutes. Seconds count. Delays in using epinephrine may be based on fears of the inappropriate administration of epinephrine. Given there is essentially no risk to epinephrine when administered via Epi-pen, nothing should delay prompt administration when anaphylaxis is suspected, even if the reaction is initially mild. Immediate referral to emergency services is also essential.

There is currently no cure for food allergies. Research into desensitization looks promising, but it’s not ready for use outside of clinical trials yet.

With Natalie’s tragedy in mind, here are some of the more common myths and facts about food allergies.

1. Myth: Allergies are a fad, and they’re not dangerous

Fact: While 50-90% of self-reported food allergies are not allergies, severe food allergies do exist. They can have a sudden onset, and be fatal in minutes. Prior reactions don’t predict future reactions. The only way to prevent reactions in those with a history of anaphylactic allergies is strict and complete avoidance of the allergen. Other types of reactions, such as celiac disease (an immune disorder triggered by gluten), require allergen avoidance, but are not immediately life-threatening like allergies can be.

2. Myth: Benadryl can be helpful for anaphylaxis

Fact: The only treatment useful for the management of anaphylaxis is intramuscular epinephrine (e.g., Epi-pen). All other treatments, such as antihistamines like Benadryl, inhalers, and steroids are secondary treatments and do not replace the need for the immediate administration of epinephrine. There is no established role for the administration of Benadryl during what is known to be an anaphylactic reactions.

3. Myth: I was exposed to an allergen, but I’m fine. Maybe I’m not going to have a reaction.

Fact: Maybe, but maybe not. Anaphylactic reactions do not always appear immediately, and can be delayed by minutes or even hours. Reactions can manifest in different ways.

4. Myth: Food allergy is the same as food intolerance.

Fact: A food intolerance is non-allergic by definition. Lactose intolerance is an example, where the reaction to lactose does not involve the immune system. Intolerances may be unpleasant but they are not fatal.

5. Myth: My naturopath/chiropractor/acupuncturist/homeopath diagnosed my allergy:

Fact: Naturopaths and other alternative medicine providers do not diagnose allergies in evidence-based ways. Yet many offer purported different diagnostic tests as part of their practice. Treatments have either been shown to be unreliable or have been demonstrated to be useless. Unproven or disproven tests for food allergy that alternative practitioners may offer include:
IgG blood tests
IgG blood tests (e.g., Hemocode and Yorktest) cannot identify food sensitivities or allergies, only recent exposure to different food ingredients. It has no established value as a diagnostic test for food allergies.
Applied kinesiology
AK is a well-known scam that is purported to diagnose allergies by holding a suspected allergen and then pressing down on that limb. Muscle weakness is said to signify an allergy. Careful evaluations show that AK tests can be completely manipulated by the tester, and they have no relationship to actual allergic responses.
Electrodermal test or “Vega Testing”
The Vega test is claimed to measure body electric currents (to acupuncture points) with an allergen in the electrical circuit. There is no correlation between Vega test results and reality, in that it cannot identify allergies at all.
Cytotoxic testing (Bryan’s test)
These fake allergy tests were last generation’s IgG blood tests, sold in storefronts, and involves mixing a patient’s white blood cells with suspected allergens. There is no correlation between the results, and allergic responses. The FDA and other regulators have taken action to clamp down on cytotoxic assay sales, but providers can still be found.
Hair analysis
While useful for testing for exposure to drugs and some chemicals, there’s no basis for examining the hair to determine allergies
Pulse test
Used more for diagnosing food “intolerance”, this involves measuring the pulse before and after eating a suspected allergen. It should be self-evident why this sort of testing isn’t advisable for suspected allergies.

6. Myth: My naturopath/chiropractor/acupuncturist/homeopath can eliminate my allergy
Fact: Despite claims that are made with regularity, there are no “cures” for allergies that exist within alternative medicine. Perhaps because of the limited treatment options, alternative purveyors offer a variety of “allergy elimination” treatments that are claimed to be effective for a variety of allergens. NAET, or Nambudripad’s Allergy Elimination Techniques is claimed to eliminate “energy blockages” through some combination of chiropractic and acupuncture treatments. Testing includes some elements of applied kinesiology (see above) and electronic devices that measure skin resistance, akin to the Vega test (see above). Not surprisingly, there is no credible evidence that “NAET” can eliminate allergies of any kind but this does not prevent its proponents from making wildly dangerous claims:
NAET

Perhaps not surprising, NAET techniques can kill.

7. Myth: “May contain” warning labels just provide legal protection for companies. Those foods are fine for those with anaphylactic allergies.
Fact: May contain labels should be taken literally. A recent study of products labelled “may contain peanuts” contained detectable levels of peanuts 8.6% of the time.

8. Myth: I diagnosed my child’s allergy so they don’t eat “X” anymore.
Fact: Many more people believe they have food allergies than actually have them. Unnecessary dietary restrictions can have nutritional consequences, so professional evaluation is warranted if food allergy is suspected.

Did I miss any? Add yours in the comments.

Posted in: Science and Medicine

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