Food allergy is a constant source of anxiety to parents of children who could in fact die or suffer a severe reaction to foods. Believe it or not, the government has done a nice job with information pertaining to public safety, in this case, food allergy in schools. In case you think I’m kidding about the severity of food allergy, the YouTube link below should change your mind. The second link from the CDC is the “official word” on food allergy in schools.
This question comes up in my office almost everyday….should I do skin testing or blood work? As you can see from the response of national experts, it depends. There is NO test that can boast 100% accuracy to predict whether or not you will react to a food. In fact, the gold standard if you will, is still the oral food challenge. Here is some food for thought (really, do you have to pun)
Clinical history is very important in determining food allergy. If you can eat a food without difficulty breathing, rash, or hives, you are most likely not allergic. You may have a positive test, but that only means you’ve had previous exposure to the food.
I will often obtain both skin testing and ImmunoCap (blood work) to clarify the presence of IgE-mediated allergy. If both tests are negative, you may have an adverse reaction to a food, not the severe life-threatening anaphylaxis. Very important distinction!
If in doubt, a food challenge is always a procedure to consider. Here’s why.
Sometimes the food in question just isn’t worth the trouble to challenge. No one says you have to eat strawberries!
If you challenge peanutsfor example, in the doctor’s office and experience anaphylaxis, better there than at home. Epinephrine is more readily available and in many cases, IV access and full resuscitation is available within minutes of your reaction.
This is another reason why a single test or treating allergy without experience is not a good idea. Read the link below and tell me just how complicated things can become!
You blurt out an insult to your girlfriend, the quarterback throws for an interception, I bought a stock that tanked….if only I could take back decisions I’ve made. We all feel that way at times, but how can a lab test be a bad decision? Continue reading Why Doctors Order Too Many Tests→
Schools are quite paranoid about giving any medication on their watch. The liability for giving sunscreen when you don’t need it? Zero. This is very similar to the use of epinephrine in a school aged child with food allergy. You certainly don’t want to withhold epi and risk anaphylaxis or death, when the risk of giving the EpiPen is negligible even if you don’t need the drug. Maybe our policies in schools will change after a large malpractice case gets media attention for NOT giving epinephrine at the appropriate time for peanut allergy.
Ok, another study about the dangers of food allergy (yesterday in USA Today). You would think the occurrence of food allergy to KNOWN allergens (peanut & milk) would decrease given all the attention given to accidental ingestion. Evidently, this is not the case. Explanations? Maybe we’re afraid of giving epinephrine. In my personal experience, giving epinephrine is analogous to “waving the white flag.” It doesn’t have to be nor should it be when treating children with suspected food allergy. As I tell my nurses, “give the epi, then call the doctor!”
What’s medicine and what’s just candy! Read on to find out. My own personal thought is many patients with vocal cord dysfunction (VCD) respond to vocal hydration which can occur while sucking on a cough drop/candy. Maybe we’ve been treating VCD all along with HALLs! Stranger things have happened.
My transcriptionists are not only good at what they do, but when they hear me talk as much as I do, it’s almost family.
I am reading a book called, Don’t Kill the Birthday Girl by Sandra Beasley, and I thought of you.
It’s a memoir about the author’s life with food allergies, what it was like growing up with allergies, etc. She has a variety of food allergies along with environmental allergies.
It’s not very long but it seemed like a book parents who have kids with allergies or individuals suffering from allergies in general would really be able to relate to. Good advice Stephanie!
The author is really honest about what it’s like living with allergies but she’s humorous about it at the same time.
The one thing that shocked me is that when the author was a teenager she thought about overdosing on Benadryl because she was tired of living with allergies. Don’t kid yourself, the quality of life in patients with allergy isn’t very good….much worse than heart disease or even diabetes.
I think this book could help people with allergies, so they don’t feel alone. I don’t feel alone but I know I’m the only one in my family with allergies and none of them get what an allergic reaction is really like so I’m really enjoying this book.
Stephanie, thanks for the suggestion and I’m sure many of our readers will also enjoy the book. You’ll have to ask her permission to “friend”, but here’s her link—>profile.php?id=1192230038&sk=photos
Patients with suspected EoE should be evaluated by both an allergist and a gastroenterologist.
A careful history should include screening for the presence of reflux/GERD, growth delay, feeding/swallowing difficulty, and a past history of allergic disease.
Symptoms of interest include history of weight loss or poor weight gain, dysphagia or odynophagia, multiple emergency department visits for impacted food, altered eating habits such as food aversions, overcutting or overchewing one’s food or eating very deliberately and requiring lots of fluids to wash down each bite.
A family history of similar symptoms or atopy can also be a clue.
EGD with multilevel biopsy is needed to make the tissue based diagnosis. Careful attention should be paid to gross features when performing the procedure. Dilation may frequently be performed in conjunction with the biopsy.
Allergen testing should be performed only in patients with biopsy proven EoE, because the tests do not have good positive predictive value without established disease. Unfortunately, skin testing can be positive AND negative in biopsy proven EoE, which leads to much confusion from a diagnostic standpoint.
Testing is guided by foods reported to cause symptoms, but should include 13 common foods with established predictive values for EoE. What are those foods? I’m glad you asked. Milk, egg, soy, wheat, corn, beef, chicken, apple, rice, potato, peanut, oat, barley. This means BOTH skin testing and patch tests to the above list. Patch testing is a bit different in that I make a “paste” with the food and place it in a Finn chamber on the back for 48 hours. Keeping it on can be a challenge, but good results.
Inhalants should also be tested given aeroallergy can play a role.Food atopy patch testing assesses for a cellular-mediated mechanism, and should be placed for food items not positive on initial testing, and read at a minimum of 48 hours after placement. Both prick and patch tests have independent positive and negative predictive values, as well as combined values. Foods positive on either test are generally recommended to be removed from the diet. There is no established role for ImmunoCAP® testing or other allergy blood tests in diagnosing EoE.
So there you have it…find out if EoE is even present before testing for foods.
Use both skin tests and patch testing to identify suspected foods that will need to be eliminated.
And in case you’re wondering, here’s what a positive patch test looks like…..
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