Monday, December 9, 2013

If food allergy deaths in food-allergic individuals are rare, do we change our ways?

This is a follow up post to 1 reason I despise science headlines.  It is in response to the recent press-coverage of Incidence of fatal food anaphylaxis in people with food allergy: a systematic review and meta-analysis  published in the journal Clinical and Experimental Allergy.

After a week of thought, I am content that a group of researchers attempted such a risk assessment given the existing literature, i.e. what is the risk to a population of food allergic individuals dying from an allergic reaction to food.  There is a real need for good, hard statistics to put things into perspective.  What I am unsure of is whether this study warranted the press coverage that it has received.  As discussed in my first post, there is a huge range of error surrounding their identified risk of death - 1.81 deaths per million food allergic individuals per year (with a statistical error that gives a 95% chance that the true value falls between 0.94 and 3.45 deaths per million assuming no bias).  However, there are real issues of possible bias, which includes but is not limited to possible medical coding errors surrounding death due to anaphylaxis and pinning down the true prevalence of food allergy.  This at least is a first attempt at systematic review/meta-analysis and certainly warrants more powerful studies to hone in on the true value with better accuracy and precision.  The bottom line is that even with obvious known flaws in their acquired value, it is very unlikely that the risk of food allergic individuals across the food allergic population dying from their food allergy will trump the risk we all face from accidental death.  The number of U.S. deaths due to accidental death is reported as 391 per million per year, according to the CDC.  The study authors certainly have noble intentions of this study reducing the anxiety faced by food allergic individuals or their caregivers.  Senior author, Dr. Robert J. Boyle, a pediatric allergy specialist at Imperial College London is quoted in a New York Times blog, “It’s a matter of not letting food allergy rule your or your child’s life.  The risk is surprisingly low. You still have to take precautions, but I think it’s important to see it in context.”
What I've been grappling with personally is - does this study reduce my anxiety level?  

Personally, this study doesn't change how our family views and deals with my son's life-threatening food allergies.  Here's why -
1.  The study generalizes a population considered "food allergic."  Not all food allergic individuals are alike.

Risk assessments are great, but there is likely quite a bit of heterogeneity as food allergic individuals go (a spectrum ranging from an obnoxious itchy mouth due to oral allergy syndrome, all the way to anaphylaxis from inhaled peanut dust).  In fact, the study authors point this out in their discussion, "While it is possible that specific groups of food-allergic people have a higher incidence of fatal food anaphylaxis, such groups cannot yet be easily identified in clinical practice."  As one example, individuals that have both food allergies and asthma may be at increased risk of fatal food anaphylaxis.  The bottom line here is that this uncertainty highlights that we are STILL relying on our allergists/medical specialists to help us navigate an unknown personal risk and our response to that risk as individuals, not as a population of individuals (i.e. the individual allergy action plan.  By the way, if you are allergic and don't have one, get one - here or here!).

My fear with the press coverage of this particular study is that people affecting policy whether it is for schools, restaurants, or airlines wrongly base a blanket decision or policy on this study's risk assessment.  Especially for schools, it is the individual plans developed with a medical professional who knows the clinical history that counts the most.

2.  Food allergy reactions are unpredictable.

As mentioned in point #1, we rely on our allergists to help us navigate an allergen-infested world based on our individual clinical history.  The fact is, though, there is no test that can predict the reaction severity to a food allergen.  Even a previous reaction history does not indicate whether the next exposure will result in itchiness and hives or full-blown anaphylaxis.  We have all heard too many tragic stories of children who previously had only minor reactions to their allergen, who lost their lives due to one misstep and fatal anaphylaxis.  The point is, because of this uncertainty, which this particular study does not address, a food allergic individual or caregiver must be prepared to act.  Given the stakes, preparedness for anaphylaxis is essential, even if the overwhelming majority of anaphylaxis does not result in death.  We just don't know who will come out of anaphylaxis ok and who won't.  Delay in administration of epinephrine is a big factor in most cases of fatal anaphylaxis.

My fear with the press coverage of this particular study is that an unaware public continues to stand by and watch an individual in the throes of anaphylaxis while waiting for emergency responders to arrive because it's "rare that food allergic individuals die from their reactions" or that they straight-up don't know what to do.  It is my hope that just like a complete stranger stepping in to do CPR for someone in cardiac arrest, complete strangers will know that they need to step up and administer epinephrine to someone in anaphylaxis BEFORE emergency responders arrive.  Likewise, there should be laws protecting these untrained "good Samaritans."  Usually allergic individuals will have an epinephrine auto-injector on them or in close proximity (child in school, for example).  Even better yet?  I have visions of epinephrine auto-injectors that are part of first-aid kits along with automatic external defibrillators (AEDs).

Two types of life-saving epinephrine auto-injectors - Auvi-Q and EpiPen

3.  Preventative measures in food allergic individuals likely contribute to the statistic

If the acquired statistic is across the food allergic population, there are certainly a lot of individuals and their families clearly going to great lengths to avoid their allergen, sometimes at the expense of a great deal of fear and anxiety.  If these preventative measures were not taken by food allergic individuals and their caregivers, it seems very plausible that the rate of fatal anaphylaxis would increase in the food allergic population.  We do not know this as scientific fact, but the study authors do cite one particular study where overall risk is likely altered due to preventative measures in the case of non-fatal food anaphylaxis.  My opinion is that this is where things get hairy interpretation-wise, and it will not likely change how individuals or their caregivers respond to their allergy.

My fear with the press coverage of this particular study is that preventative measures may be taken less seriously for individuals where the risk truly is perceived as higher than normal by an allergist.  On the other hand, it may give a skeptical public more fodder to argue against necessary accommodations for food allergic individuals who truly need it.  Are there individuals who under or over-estimate their real risk?  You bet.  There is a very delicate balance between prevention and risk, and this is where the individual plan with your medical professional will help.  I REALLY can't wait for the day when we can get a handle on real risk for each individual.  Better yet - how about a cure!

The positives from this study -
It is a good start to get at hard numbers for those of us trying to grapple with risk versus quality of life - a constant daily battle it seems.  I believe that there a lot of people out there, especially parents and caregivers, that deal with a lot of unnecessary fear and anxiety.  Adults with allergies that I have talked to tend to handle their risk, know their bodies, and can respond accordingly, while not compromising their quality of life (they do get frustrated by an unaware public, don't get me wrong)!  Children and teens are a different story.  So much fear and anxiety comes from how life-threatening food allergies are handled in public where we rely on others to understand allergies, know the risks (e.g. cross-contamination of food), and how to respond to an emergency.  As a parent, I HOPE that I have done my job to educate all of those I entrust my son to, but I still worry (A LOT!) when he is not in our immediate care. 

Where to go from here -
Again, this is a start. As promised in my first post, I want to bring up the recent study in the Journal of Allergy and Clinical Immunology, funded by the Asthma and Allergy Foundation of America, Anaphylaxis in America: The prevalence and characteristics of anaphylaxis in the United States. This is a first of its kind study that actually gets at the lifetime prevalence of anaphylaxis in the U.S. adult population - at least 1 in 50 U.S. adults has had one or more anaphylactic episodes with the actual number quite likely higher than that. Out of these cases, 31% are reported as food-related anaphylaxis (the study authors point out that this value is likely much higher in the pediatric population). Anaphylaxis is not a rare event by any means, and the good news is that most people survive. Wouldn't it be great to see this type of data combined with the incidence of food-related deaths due to anaphylaxis? In my opinion, this type of risk assessment would be more meaningful. Food allergy encompasses a huge spectrum of allergic individuals, many of whom may never experience full-fledged anaphylaxis. Really what I want to know is for cases where anaphylaxis occurs, how often does death happen. There will certainly be some of the same bias issues that the Clinical and Experimental Allergy paper has, but at the same time, it would give those of us who are at increased risk of anaphylaxis a better sense of the actual risk should anaphylaxis occur.

A final take-home point is that the study also found that about half of all individuals who had anaphylaxis did not have a prescription for an epinephrine auto-injector or an emergency action plan. The authors conclude, "Taken together, the results of these surveys indicate a pressing need for improved public health initiatives regarding anaphylaxis recognition and treatment." I couldn't agree more! We need the general public (and non-allergy/immunology clinicians who aren't referring patients to board-certified allergists!) on our side - not seeing this as a ridiculous inconvenience or a one-off occurrence, but that anaphylaxis is very real and potentially life-threatening. We can't predict when anaphylaxis will occur and who will come out of anaphylaxis or not. Even if death is rare, any death is one too many.


Kids with Food Allergies Foundation hosted a FREE webinar led by the lead study author himself, Dr. Robert Wood, division chief of allergy and immunology at Johns Hopkins University. (You can watch it here). He is easy to follow and answered many questions beyond the scope of this study which relate to risk and prevention!


References are hyperlinked throughout the text in the appropriate places.
Prevention strategies may still feel like a daily grind. And treating anaphylaxis may still be anxiety provoking. But when given multiple tools and personalized, research-based patient education and support, families coping with food allergy and risk for anaphylaxis can conquer fears and thrive! - See more at:
Prevention strategies may still feel like a daily grind. And treating anaphylaxis may still be anxiety provoking. But when given multiple tools and personalized, research-based patient education and support, families coping with food allergy and risk for anaphylaxis can conquer fears and thrive! - See more at:

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