Sunday, April 22, 2012

Egg-cellent news



Thursday was a stressful day to say the least. It was food challenge day, and it marks the first time in living with food allergies that hope may indeed be reality.

So, when does this egg story begin?  December of 2009 marks the last time that JR, our handsome young 1 year old at the time, ate anything with eggs.  Before that point, JR regularly devoured scrambled eggs.  Like any parent, I enjoyed watching my growing boy enjoy such a wonderful source of protein.  But in December 2009, the immune "switch" was flipped and our joy quickly turned to terror as scrambled eggs suddenly evoked the scariest of immune system responses, anaphylaxis.  Vomiting, lip swelling, hives, coughing - all within 5-10 minutes.  The incredible, edible egg suddenly became not-so-incredible and definitely not edible.  For JR, eggs were poison.  (As a side note, a few weeks after the scrambled egg incident, we learned the hard way that "made on shared equipment" labels should be heeded.  Mac n Cheese made on shared equipment with egg-containing foods caused the same reaction.  We were novice food allergy parents, and absolutely heart-broken to have put JR through that terror.  JR was ridiculously sensitive to trace amounts of egg protein).

Fast forward to 2012.  Every year since 2009, JR has been tested through a blood test (RAST) for the presence of antibodies to egg protein.  You know, those same antibodies that protect us from disease?  Well for the food allergic, the immune system erroneously targets innocuous substances like eggs.  This year, the antibody level was at the threshold of being positive.

The antibody (dark green, Y-shaped structure) binding to antigen (light green circle).  In Ian's case that antigen is the "harmless" egg protein.  C'mon, immune system. Since when were eggs worse than the plague?!
Photo source:  http://www.nwfsc.noaa.gov/hab/habs_toxins/marine_biotoxins/detection/elisa.html

Hope, but not proof. 

If only it were as simple as measuring antibody levels in the blood.  Due to the unpredictable nature of the immune system when it comes to food allergies and the large error inherent to allergy testing methods, the definitive proof is the food challenge.  To put it more bluntly, this is the "test" where you go to the doctor's office and consume the offending food... and wait.  Will there be a reaction?

On a very rainy Thursday afternoon, JR and I headed into the doctor's office with 3 hard-boiled eggs and an i-Pad loaded up with Disney movies (for the waiting part).  JR was chipper.  I was terrified.  I remember what happened two and a half years ago.  I'm not sure that JR does. As a scientist, I know this "test" is necessary to confirm the egg allergy is gone (or not), but at that moment, I would have given anything to not have my son be a subject in this test.  But, hey, at least we were in the best place should a reaction occur, right?!

The egg-cellent news

Step 1 - scratch egg into the skin surface and wait (watch the Lion King)... no reaction.
Step 2 - rub egg on lips and wait (Simba just can't wait to be king)... no reaction.
Step 3 - eat a bite of egg and wait (Hakuna Matata)... no reaction.
Step 4 - eat more egg and wait (Lion King done, 4 year old takes over)... no reaction.
Step 5 - try and eat even more egg (4 year old loudly resists)... no reaction.
Step 6 - resort to every form of bribery known to parents to convince 4 year old he should eat more egg... no reaction.
Step 7 - half an egg finally goes down the gullet and Dr. agrees half an egg (instead of a whole egg) is sufficient for the test - no reaction.
Step 8 - relief and a dinner of ice cream and chocolate chips :).

It turns out, we're not quite out of the woods just yet.  Apparently, there is a small chance that the immune system could come back with a roaring vengeance to egg.  For one month, we will avoid eggs altogether.  At the end of the month, JR will be given a blood test to look for antibodies against egg.  If the antibody levels are still extremely low, JR is given the ok to eat egg!  And there will be cake, and cookies, and french toast aplenty.

Scientifically, the immune system is not my area of expertise, but I am in expert in what food allergy parents go through.  As a parent and a scientist, I can't help but wonder why in the world a medical community capable of successfully transplanting vital organs, doesn't have more reliable, indirect methods of allergy testing (e.g. any other test besides the direct food challenge test?!).  What is it that we lack in our understanding?  Finally, if JR has indeed outgrown his egg allergy, what has changed?  What has turned that immune system "switch" off?  If we can understand what turns that "switch" off, then we may just have a cure for food allergies.  I'm not an expert in the immune system scientifically, but I make it my goal everyday to try... for JR and for all of us that are walking on eggshells when it comes to food allergy.

Let's turn the food allergy switch off.