Food Allergy Test: What Does It Mean?

What You Need to Know About Diagnostic Allergy Testing

 by David Stukus, MD

 

Whenever I meet with families for the first time and ask the parents whether their child has any food allergies, I often hear the following reply: “I don't know, he/she's never been tested”. This always presents a wonderful opportunity to discuss the role of diagnostic testing for food allergies, as I'd like to do in this forum.

 

Before we go any further, I'd like to define some common terms that you may encounter when reading about or discussing food allergies:

 

  1. Allergy – This is an immune response to a particular food. Symptoms should occur every time that food is ingested.  These immune system changes fall into two categories:  Immunoglobulin E (IgE) mediated and non-IgE-mediated.
  2. Sensitization – This is the detection of specific immunoglobulin E (IgE) through skin prick or blood testing towards a specific food, but without the development of symptoms after that food is ingested. In other words, a positive allergy test result to a food that your child has eaten without any problems, or has never eaten.
  3. IgE mediated hypersensitivity/allergy – Commonly referred to as “food allergy”, in which IgE antibody specific for a food is formed and attaches to the allergy cells throughout the body. Whenever that food is ingested, it causes immediate onset symptoms, usually within minutes or up to 3 hours after ingestion. Typical symptoms include hives, swelling, itchy/water nose and eyes, difficulty breathing/swallowing, vomiting, and can progress to loss of consciousness. Skin prick or blood specific IgE testing is very likely to be positive for that food.
  4. Anaphylaxis – Rapid onset, progressive, severe symptoms involving more than one organ system that can occur with IgE mediated food allergy.
  5. Non-IgE mediated reaction – This is an immunologically mediated, typically delayed-onset reaction to a particular food. This is mediated by other parts of the immune system separate from IgE, specifically T-cells. These symptoms are not immediate in onset and can occur hours to days after ingestion. Anaphylaxis is not part of this response and most symptoms involve the gastrointestinal tract, with vomiting, upset stomach, diarrhea, or blood in the stool. Skin prick or blood specific IgE testing is negative.
  6. Sensitivity or intolerance – This is a non-immunologic response to a certain food or foods. Symptoms occur when that food is consumed, but may be variable over time. This also most often includes gastrointestinal symptoms and does not include symptoms observed with IgE mediated reactions. Skin prick or blood specific IgE testing is negative.

 

When trying to determine whether a child has a food allergy, there are many steps involved. First, the most important part is taking a careful history of suspected foods, the timing and types of symptoms that occur, and any treatment that has been used to help make symptoms better. If the history is consistent with an IgE mediated allergy, then testing is often pursued. However, a good rule of thumb to remember is, if your child can eat a food without developing any symptoms, then they are unlikely to be allergic to that food. Why is that? Because the best test is actual ingestion of the food. In regards to IgE mediated allergy, you're almost always going to know if a certain food makes your child sick, and there are no 'hidden' food allergies. In many circumstances, the history is more consistent with non-IgE mediated symptoms or intolerance and skin prick or specific IgE testing is not helpful, necessary, or indicated. This is the point when many families ask, “Why don't we just do the allergy tests to find out for sure?” If only it were so easy.

 

Before we discuss any further, I'd like to mention something that is very important to keep in mind when discussing food allergy testing. A positive test result for food allergy is not, in and of itself, diagnostic for food allergy. These tests are best utilized to help confirm a suspicious history for IgE mediated food allergies. They have high rates of falsely elevated and meaningless results and are not useful screening tools.  Some commercial laboratories offer convenient “screening panels”, in which many different foods are included. These are rarely utilized by Allergists/Immunologists, but more commonly ordered by primary care providers. This often results in falsely elevated results, along with diagnostic confusion and unnecessary dietary elimination. Ultimately, your child may have food(s) removed from their diet for no reason other than a meaningless positive test result. This may then lead to anxiety, family hardship due to food avoidance, and potentially nutritional deficiencies.

 

There are 3 main ways to test for IgE mediated food allergy:

  1. Skin Prick Testing (SPT): This involves placing a drop of allergen onto the surface of the skin, and then pricking through it to introduce the allergen into the top layer of the skin. If specific IgE antibody towards that allergen is present and attached to the allergy cells, then an itchy bump and surrounding redness (wheal/flare) should develop within 15 minutes. These tests have a high negative predictive value (when a test yields a negative result, it is very likely to be correct), but a low positive predictive value (when a test yields a positive result, it is less likely to be correct) which can result in false positive test results. Thus, it is not a good screening tool but is a very reliable test to confirm a history that is consistent with an IgE mediated food allergy.

    In order to get accurate results, all antihistamines should be discontinued for 5-7 days before testing. A common myth is that skin prick testing is not reliable in young infants and children. Actually, skin prick testing to foods is reliable at any age if you have a history of IgE mediated food allergy.  Tests may be negative in young children when they are performed for other conditions such as non-IgE mediated formula or food intolerance.

    TAKE NOTE: "Positive" results can be wrong; "negative" results are more likely correct.
  2. Specific IgE (sIgE) Blood Testing (previously and commonly referred to as RAST or ImmunoCAP testing): This test measures levels of specific IgE directed towards foods in the blood. The range, depending upon the laboratory techniques, can go from 0.10 kU/L to 100 kU/L. This also has a very high negative predictive value but a low positive predictive value. Mildly elevated results are often encountered, especially in children who have other types of allergic conditions such as eczema, asthma, and allergic rhinitis. The predictive values for likelihood of an allergy being present differ with every food, but in general, the higher the level, the more likely that an IgE mediated allergy is present. This is also a very poor screening test due to the high rates of falsely elevated and meaningless results.

    I've met many families whose children have been ‘screened for food allergies’ in the setting of eczema or other conditions and the report lists every food that was tested as being ‘high’, as their cutoff for reporting this is often set very low, at levels that are usually meaningless. This leads to diagnostic confusion and unnecessary dietary elimination. In addition, many laboratories will report an arbitrary class designation (a created value that is assigned to a result that has no meaning or scientific basis), along with the actual level of specific IgE obtained. This is of no clinical use and also does not help determine whether food allergy is present.  It is also commonly misunderstood that higher blood test levels indicate increased ”severity”.  Unfortunately there is no test that can determine severity. Individuals with higher blood (or skin) tests are at no more increased risk of anaphylaxis than someone with minimally positive tests.

    TAKE NOTE: "Class Levels" are meaningless.
  3. Physician Supervised Oral Food Challenge (commonly referred to as IOFC on KFA):This entails consumption of gradually increasing amounts of the suspected food allergen while being supervised by a physician, usually an Allergist. If no symptoms develop that are consistent with an IgE mediated food allergy (hives, swelling, anaphylaxis), then it makes the presence of IgE directed toward that food unlikely. This is often considered the gold standard for food allergy testing, and can be considered a good way to ‘rule out’ food allergy or determine if a previously diagnosed food allergy has gone away. This is time consuming as most challenges take 4-8 hours to complete but can be a very reliable test.

    TAKE NOTE: The gold standard for diagnosing a food allergy is through a physician-supervised oral food challenge.

 

As you can see, performing diagnostic testing for food allergies can be very complicated and requires careful consideration about what tests to order and how to interpret them. There are very few indications to perform an extensive ‘screening panel’ for food allergies. However, obtaining a careful history of what specific foods cause symptoms and then using the type of symptoms can be a helpful guide to determine whether specific IgE testing is worth pursuing, or to go in a different direction.

 

Lastly, a word of caution regarding other commonly used techniques (often utilized by non-board certified Allergists/Immunologists) that you may encounter. Specific IgG blood testing for foods, muscle provocation testing, acupuncture, hair/urine analysis, and applied kinesiology are not validated, standardized, or FDA approved tests for the diagnosis of food allergy or food intolerance. Use of these tests is not recommended by the American Academy of Asthma, Allergy, and Immunology, or supported by the Guidelines for the Diagnosis and Management of Food Allergy, published in 2010 (Journal of Allergy and Clinical Immunology, 126(6); supplement S1-56).

 

References

Guidelines for the Diagnosis and Management of Food Allergy, published in 2010 (Journal of Allergy and Clinical Immunology, 126(6); supplement S1-56).


 Dr David StukusDr. Stukus is an Assistant Professor of Pediatrics in the Section of Allergy/Immunology at Nationwide Children's Hospital, in Columbus Ohio. In addition to his interest in caring for families with food allergies and other allergic conditions, he also serves as Co-Director of the Specialty Asthma Clinic. He previously completed his pediatric residency at Nationwide Children's Hospital and his fellowship in Allergy/Immunology at the Cleveland Clinic Foundation. He is married with one 3 year old son, and a daughter due in November.

 

 

Attachments

Photos (1)

Add Comment

Comments (40)

Newest · Oldest · Popular

Hi, and welcome, @AGlick0927! Hugs on the reactions and the conflicting test results on peanuts. You're definitely in the right place to get support!

Your questions are great, and it sounds like you still have some things you might want to discuss with your allergist. 

Another thing you might want to discuss with your allergist is component testing for both milk and peanuts, if you haven't already done so. Component testing can tell a doctor what particular protein in milk or peanuts a person is sensitive to, and that can help the doctor decide whether an oral challenge is appropriate. 

Since you guys are planning on doing an oral challenge, KFA has a great resource on oral food challenges

Why not post this question to our Main Support Forum so you can get more feedback from other folks in a similar situation? If you're on desktop view, just follow the link above, and click on the big green POST. On mobile, click the three horizontal lines in the upper left hand corner, and you'll see POST. Click that, and you'll be able to add your comment as a new post.  

Hello! My 2.5 year old daughter has tested positive to peanuts, tree nuts, egg and dairy on a skin test (2 different times) She has had reactions to both egg and dairy, however she has never ingested any nuts.

We just received the results of her first ever blood test and it confirmed egg and dairy, however it came back negative to all nuts! We will be scheduling an in office peanut challenge.

My question is, since I know that false negatives are more rare than false positives, should I feel optimistic that we actually have a chance at not being allergic to peanuts or tree nuts?

Additionally, our allergist is suggesting we do a BAKED milk challenge based on numbers, however this scares me because I've seen her reaction to dairy in the past and I hate to think of having to go through that again.

Thank you so much!

Hi, Lune! Since you're having symptoms when you eat food, I agree with Jen -- a board certified food allergist is definitely someone to consult. You may also want to touch base with a dermatologist as well.

Why not post this question to our Main Support Forum so you can get more feedback from other folks in a similar situation? If you're on desktop view, just follow the link above, and click on the big green POST. On mobile, click the three horizontal lines in the upper left hand corner, and you'll see POST. Click that, and you'll be able to add your comment as a new post.  

Your comment caught my eye because my DD has an allergy to apple that is in line with something called OAS (oral allergy syndrome). You can find out more about it under KFA's resource on the types of food allergies.

Also, my DD had/has eczema (worse when she was little, better now as a teen), and I have flare ups of eczema on my eyelids.

Not all eczema is related to foods, and even if a food is a trigger for eczema, some allergists and dermatologists recommend other techniques besides avoiding that food. You can find some of those techniques here on KFA's resources for eczema

So as far as I remember I suffered with bad eczema rashes since I was little and my parents somehow managed to keep it at bay. No nuts, dairy and limited amount of citrus acidic and sugar food, I have had no issues with eczema for more than ten years and thought it went away--- I was wrong. I recently started having bad eczema flare upd around my face. Eyelids, under eyes, chins and around mouth. It's swelling, itchy and bumpy and I have no idea what is causing it. I have been eating nuts, dairies and acidic food without no problems but something (could it be environmetal?) is triggering it pretty bad. I am very curious about testing for food allergy but please let me know if you have any recommendations for different types of testing.

Also, I have been loving seafood all my life even as a kid but I found out recently that after consuming salmon or tuna my face feels little itchy. Same goes for apple and cherries. I love eating them but my mouth gets so itchy after and my lips swells. Could I have developed some kind of food allergy? And how do I manage it if I can't give up on eating them? 

Mehmet posted:

Can somebody be okay eating a food but not be okay touching it? 

My daughter (5 years old) successfully passed two oral food challenges for hazelnuts, which included eating increasing amounts of hazelnuts and also a spoon full of Nutella (this was given after she had eaten her last dose of hazelnuts). There were no symptoms or problems at all. So I (and our allergist) think it's safe to assume that she is no longer allergic to hazelnuts and we are obviously very grateful for that. 

However, whenever we give her Nutella at home and something gets stuck around her mouth or on her lips, her skin reacts. The skin turns red (not itchy though) and her lips "hurt" a little bit (that's her description, it may be itchy). This disappears quickly after we wash it off with water.

We've check all the other ingredients in Nutella but everything seems to be fine. Any idea of what could cause these reactions. Our allergist suggests that she may just have sensitive skin. I hope that's the case but why the bumps on her lips then?     

Welcome Mehmet!

May I ask when you did two food challenges?  Just curious...

Does she have any other allergies?

The redness and the lips "hurting" would have me think that she could possibly still be allergic to it.  How much is she eating at home?

As Cynthia mentioned, be sure to visit us in our Main Support Forum where others can chime in as well with their experiences.

Can somebody be okay eating a food but not be okay touching it? 

My daughter (5 years old) successfully passed two oral food challenges for hazelnuts, which included eating increasing amounts of hazelnuts and also a spoon full of Nutella (this was given after she had eaten her last dose of hazelnuts). There were no symptoms or problems at all. So I (and our allergist) think it's safe to assume that she is no longer allergic to hazelnuts and we are obviously very grateful for that. 

However, whenever we give her Nutella at home and something gets stuck around her mouth or on her lips, her skin reacts. The skin turns red (not itchy though) and her lips "hurt" a little bit (that's her description, it may be itchy). This disappears quickly after we wash it off with water.

We've check all the other ingredients in Nutella but everything seems to be fine. Any idea of what could cause these reactions. Our allergist suggests that she may just have sensitive skin. I hope that's the case but why the bumps on her lips then?     

We often mess up between food allergy and food intolerance. Food allergy usually comes on suddenly. Even a small amount of food can trigger an allergic reaction. Food allergy appens every time you eat that particular foo and can be life-threatening too. On the other hand, food intolerance generally comes on graduall and occurs when you eat a lot of that particular food. It is not life-threatening

Dr. Stukus -

Thank you for sharing this information.  I agree with much of what you had to say and wanted to know if you would ever recommend the "Gold Standard" for accommodations in school?  I have two children with close to 40 ER visits between them for allergic reactions.  One has had RAST scores over 100 to Peanuts since infancy - he is 12.  The other has RAST over 100 to Dairy and Eggs since infancy - she is 8.  They both had systemic reactions to skin testing done last summer.  They were denied accommodations in school under their 504 plan so, we went through Due Process litigation to get those accommodations.  The Dr who testified for the school district is a very well known pediatrician / advocate in the food allergy community.  She has never met my children, never performed skin testing or treated patients for food allergies.  She testified that she was not so sure that our children even had food allergies since our Allergist (with 40+ years of experience - including work at National Jewish) had failed to perform the oral food challenges on our kids.  Our Allergist testified that our children are contact, airborne and ingest to their allergens based on their history, skin and RAST tests.  Because of the pediatrician's testimony and her experience in the food allergy community, the judge ruled with her recommendation of oral and inhalation food challenges for both of our children.  The judge stated that because we failed to provide the burden of proof by submitting our children to both oral and inhalation challenges that the school district would not have to accommodate our children.  Would you ever advise a patient to undergo an oral food challenge under such a circumstance?  What are your thoughts?  Thanks!  

Missy24, sorry to hear that your son had a severe reaction to cashew. Unfortunately you can develop allergies at any time, so in his case he was not allergic before but then became allergic.  The article is referring to testing positive to a food but being able to eat it without reaction.  Some docs will run a panel to whole list of foods, even if the patient has only reacted to one.  This can lead to avoiding more foods than is necessary as there is a high chance of false positives with allergy testing.

My son ate cashews by the handful with absolutely no reaction and then went into anaphylactic shock after eating one.  How does that fit into this?  This stated that if you can eat something without reaction you aren't allergic.  He reacted to walnuts which now that we've had testing are still high but lower than both peanuts and cashews.

Regarding the MRT and it's usefulness for the treatment of food sensitivities, not food allergies... The absence of a particular type of reference on PubMed does not denote the absence of clinical utility in the treatment of the targeted disease states, especially for newer emerging complementary treatments.The establishment of clinical utility of new complementary treatments usually precedes the appearance of references on Pubmed, often by many years.

Dr. Stukus, I will be happy to send you information on MRT as well as contact info for physicians who use MRT in their practices.

I find it difficult advocate a blind elimination diet for type 3 & 4 food hypersensitivity (non-IgE-mediated reactions),when a test to detect type 3 & 4 food hypersensitivity,w/proven 93% accuracy,is available. Not only does the blind elimination often prove unsuccessful in detecting triggers of symptoms, but poses the risk of malnutrition,particularly in children.

 

 

 

Yes, we've been seeing allergists since she was 6 or 9 months old.  We have moved a couple of times and had to switch allergists and it can be confusing, some say lip swelling alone is anaphylaxis, what she had with banana and mustard, and some say it's not.  It's hard when allergist's don't agree. 

Maggie - I would say discussion about egg free flu shots is outside the scope of this particular blog post - but I can tell you we will be doing a blog post in the near future about egg allergy and flu vaccine, so that should provide some more insight on this issue. Stay tuned!

 

Deidre - negative test results are usually accurate, but in a small percentage of cases, children can react with negative test results.  That is why it's important to get evaluated by an allergist, since they are most qualified to sort these types of situations out (and not rely on test results alone). Glad to see you are working with an allergist!

 

Gale - Thanks for the suggestion.

My daughter (now 16 years old) was diagnosed at age 2 and had two subsequent positive skin tests to peanuts and tree nuts, but has never had a reaction at all other than her first (to walnut) at about 1 yr old. So I was hoping that the peanut positive was a false positive all along. We had component testing done recently, using the Uknow peanut test through Phadia (Thermo Fisher Scientific) which we were told was more comprehensive and accurate and the results show a severe peanut allergy. I'd like to learn more about component testing (in layman's terms).

The predictive values for likelihood of an allergy being present differ with every food, but in general, the higher the level, the more likely that an IgE mediated allergy is present.

My daughter actually tested negative several times to some things as a baby despite reacting to them and then went on to test positive with low numbers.

 

With egg for example her IgE was about 1.2, but she failed the in office food challenge with the initial dose of egg powder before the real food.

 

She also tests positve with 1.92 and 1.98 to mustard and banana but just a tiny pin prick amount of her first taste of mustard her lip swelled up like a duck, and with 1/4 of a banana the same.

 

Her dairy allergy is over 100 and is her worst, but with these others at 1.9 she still has big reactions.

 

Also as a baby she tested negative to egg and banana but had reactions to them, it wasn't until a couple years later that the test even came up positive, after we retrialed to be sure and she indeed reacted to them again.

 

So the:

 

"negative" results are more likely correct.

 

Didn't fully work with us either.

 

Recent research shows that the flu shot is tolerated by almost everyone with an egg allergy: http://www.kidswithfoodallergies.org/resourcespre.php?id=163&title=Is_the_flu_vaccine_safe_for_egg_allergy?

 

My son gets his flu shot in divided doses in the allergist's office.  He is anaphylactic to even trace amounts of egg and has never had a reaction to the flu shot. Our allergist says that in recent years, the amount of egg protein in the flu shot is almost nothing.  Before my son developed asthma, I was not too concerned about the flu shot, but now that he has been shown to be high-risk for developing complications from the flu, I am want him to have the shot in the safest manner possible.

 

Perhaps you can ask your allergist if he will give the flu shot in an office setting?

I had my son tested IgE with an allergist because of his eczema condition.  We knew his allergy to milk at age of one, hives right after 1 oz of whole milk.  He was bs mostly the first 6 months, then alimentum after.  He had regular Similic couple times before 6 months but no reactions.  His IgE for milk is 6.29, so I think it confirmed his milk allergy. He is still on alimentum and he is 16 1/2 months.

 

His IgE for egg white is above 50, I had not introduced egg to him yet, but with the MMR (had egg in it) at 15 months he had no reaction that I noticed.  He had flu shot last year at 6 months which his pediatrcian said no egg in it.   Now the allgist wants him to stay away from egg completely including flu shots, and have Epipen with him at all time.  I can NOT find anything with egg-free flu shot online. Will have to check with his pediatrcian again next appt.  Do anyone knows about egg-free flu shots?  

 

He had hives after flaxseed and IgE is 18. Fish (Cod) and Nut (Almond) are 13,  sesame is 4.7, peanut and soy are above 3.

 

His allegist wants him to stay away from milk, egg, fish, nuts, seeds, soy and peanuts, and he had reaction to egg and flaxseed only.  Any thoughts? 

 

His dust mite IgE is also 50+, had ordered dust covers online already, see if it helps. 

I would say that EE and testing is another complicated topic best addressed with its own blog post in the future and the issue of behavioral reactions to foods is another one outside the scope of what this blog post was intended to cover. Both would best be addressed in a future blog post as well. Thanks for your suggestions!

Any thoughts or direction on behavioral issues due to food? My now 6 year old daughter never had any stomach issues, eczema, or anything else, but she became absolutely uncontrollable (threatening to kill me, punching, kicking)after a strep infection back in February. I figured something had to have happened and had the doctor do all the gluten related bloodwork since it was just not her and her oldest brother is GFCF. Sure enough, it came back positive. The allergist put her on an elimination diet and we found she reacts just as strongly to corn - again only with behavior. Didn't show up with his tests so he thinks I'm a lunatic but about 36 hours after eating something with corn, her behavior starts going downhill and it takes over a week to get it all back out of her system. How do I find a doctor who will take me seriously and not just blow me off because he doesn't see a physical reaction?

Lindsay - right.  Good doctor-patient partnerships are key, especially for complicated cases such as eczema. As Dr. Stukus indicates, the evaluation and care for complicated eczema cases needs to be individualized for the child.

 

Thank you for posting your comments!

Originally Posted by Jennifer Roberge:

Thank you for this very detailed explanation. However, I'm not sure I agree with this statement "if your child can eat a food without developing any symptoms, then they are unlikely to be allergic to that food." My son has tested negative to pretty much every allergy skin prick and blood test - only positive to hazelnuts one time and walnuts another time, both in skin prick tests. He suffered from severe eczema, head to toe, and we were looking for answers. There was no particular food that seemed to cause the eczema and he didn't suffer from any immediate allergic reactions - his eczema had developed slowly since birth. Since the allergy testing was inconclusive, we eliminated dairy, soy, gluten, some tree nuts, and corn for 30 days. His skin cleared up within days of starting the elimination diet. We added each of the foods back in slowly, each one over a four day period, and his reactions were obvious - instant itching, redness around the mouth, eczema within a few hours. With dairy he wheezes and has a mild asthma attack. Many of these are IgE mediated as you described above, I believe. So, the reason I disagree with your statement above is that it seems in some cases, if a child consumes a food they are allergic to (not anaphylactic) on a daily basis, it is possible allergy symptoms will not be obvious because the reaction is so gradual. If the food is removed completely for a given amount of time and cleared from the body, then you can see the body's true reaction to the food instantly.


I look forward to your comments.


Thank you.

Jennifer Roberge

Jennifer - I absolutely agree with you.  Sitting in a lab room for one day while they have them ingest a suspected food is not going to lead to a diagnosis because many reactions, as you note, occur after gradual built up ingestion has occurred.  My son was exactly the same way!.  Elimination diets are the best as your story clearly shows!  But they require observation over time...not in one visit.  Parents need their doctors to explore the elimination diet idea and trusting what a parent reports in a food diary.  Parents need their doctors to be on the same team - without it we feel frustrated, alone, and embattled. 

My son had a myriad of issues including stomach, bronchial, and behavior - only after I eliminated foods myself did I find the sources causing the issues - none of which the allergy testing helped find.

Lindsay

http://www.mypickyglutenfreekid.blog.com/


 

Hi MulanMommy -
 
It's incredible what food can do to the body - good or bad. In our son's case, he now has severe reactions, borderline anaphylaxis, with dairy, soy, gluten, corn, and tree nuts. He can not even have one bite - or a trace. Still also triggers eczema. He used to be very sensitive to tomatoes, red pepper, and cantelope, but now that his eczema is under control, he can eat these things every few days, but as you said, never more than two days in a row. The same with coconut.
 
So interesting.
 
Thank you to Dr. Stukus for his reply.
 
Jennifer
 
 
Originally Posted by MulanMommy:

Jennifer: AGREED!!! DS was tested low score on WHEAT & SOY both skin test and blood test, we never took it seriously only avoided wheat by itself (wheat bread) and soy by itself (tofu, soybean..etc) but since birth he had eczema and stuffy nose throughout the year. We thought it's more related to seasonal/weather, but his skin problem and congestion issue lasted through summer-winter, hot OR cold seasons; we also thought it's environmental (dust mite) so we changed to special pillows/ beddings, but all of these effort only helped a bit- until our allergist told us we should totally eleminate ALL WHEAT/ SOY PRODUCT from DS diet. She even garenteed us after we try for a couple of months we will defenietly see improvements. It has been difficult, but after less than a week we saw MAJOR improvements!! My son no longer wakes up rubbing his nose, no longer need x2-x3 pillows during sleep, most of all, his skin cleared up like a BABY!!! I have never ever seen his skin so clear & smooth since birth, and he is 6 years old now!! He still have no problem if acidentally consumed wheat or soy product (before the diet change he ate them on a daily basis) he will not break out right away in rashes, but if he continually eats food contains wheat/soy for couple of days he will start having eczema/ itching and there would be some rash here and there which he scratches and is really bothersome for DS. For some reason it also dramatically effects his mood if he consumed too much wheat/soy. DS becomes hyper with short temper and a bit out of control (attention deficit), doesn't sleep well at night and gets tired easily during the day. Our allergist said although he might not breakout right away, but these are "trigger foods" for him that will built up in his system. DS lgE score is close to 1000.

 
I'd like to thank everyone for posting such wonderful comments. I'd like to address two topics that were mentioned so far:
 
1. Eczema and food allergies can be a very difficult and complicated topic, which may need it's own blog post in the future. While I can't give out specific medical advice in this forum, I am happy to help elaborate a bit more. In general, the majority of children with eczema do not have an external cause of their skin condition. Eczema is a genetic, chronic, skin condition that manifests with intense itching, loss of moisture from the skin, and inflammation (redness). Most children improve after the first 2-3 years of life. While eczema is something that they are born with, there are many factors that can exacerbate eczema, often called triggers. Common triggers include weather, illness, stress, exposure to scented topical products including soaps and detergents, and lack of regular moisturization. Some children with moderate to severe eczema that it is difficult to control despite following a thorough daily skin care regimen and use of topical corticosteroids may have foods or other allergens contributing to their eczema flares.
 
This is where it gets very tricky. Some children may have worsening of their eczema within hours of eating a food, whereas others may not experience a flare until days later, or only with regular ingestion of a particular food. The history is not always reliable in identifying which foods may be making eczema worse. In addition, specific IgE testing through skin prick or blood testing is not always reliable or helpful, either. We often find many falsely elevated results, which leads to a lot of confusion and unnecessary dietary elimination. On the flip side, there very well may be an immunologic reaction taking place that has nothing to do with IgE, thus testing is negative, but eating a specific food may still worsen their eczema. Trial elimination or introduction diets can be very helpful in these cases. In almost all instances, this is a complicated issue that is best handled on a case by case basis, in consultation with your Pediatrician and/or Allergist.
 
Keep in mind that there are always exceptions to every rule, and the above information may not apply to your specific situation, thus the need for individualized care.
 
2. The MRT/LEAP test is not a validated or standardized test for the evaluation of any form of food allergy or sensitivity. It definitively has no role in the evaluation of suspected IgEmediated food allergy. A search for this test as validated by any published study via PubMedfailed to reveal a single reference to it. It is not recognized by the governing bodies for Allergists/Immunologists (AAAAI/ACAAI) as a useful diagnostic tool for evaluating the role of foods contributing to any specific condition.
 
-Dave Stukus

For those of you posting about eczema - you are invited to join us in our Asthma, Eczema and GERD forum as well!  Just log in as you did to comment on this blog, and scroll down the list of forums to find it. Or you can go there directly by clicking here. We'd love to have you join us!

Jennifer: AGREED!!! DS was tested low score on WHEAT & SOY both skin test and blood test, we never took it seriously only avoided wheat by itself (wheat bread) and soy by itself (tofu, soybean..etc) but since birth he had eczema and stuffy nose throughout the year. We thought it's more related to seasonal/weather, but his skin problem and congestion issue lasted through summer-winter, hot OR cold seasons; we also thought it's environmental (dust mite) so we changed to special pillows/ beddings, but all of these effort only helped a bit- until our allergist told us we should totally eleminate ALL WHEAT/ SOY PRODUCT from DS diet. She even garenteed us after we try for a couple of months we will defenietly see improvements. It has been difficult, but after less than a week we saw MAJOR improvements!! My son no longer wakes up rubbing his nose, no longer need x2-x3 pillows during sleep, most of all, his skin cleared up like a BABY!!! I have never ever seen his skin so clear & smooth since birth, and he is 6 years old now!! He still have no problem if acidentally consumed wheat or soy product (before the diet change he ate them on a daily basis) he will not break out right away in rashes, but if he continually eats food contains wheat/soy for couple of days he will start having eczema/ itching and there would be some rash here and there which he scratches and is really bothersome for DS. For some reason it also dramatically effects his mood if he consumed too much wheat/soy. DS becomes hyper with short temper and a bit out of control (attention deficit), doesn't sleep well at night and gets tired easily during the day. Our allergist said although he might not breakout right away, but these are "trigger foods" for him that will built up in his system. DS lgE score is close to 1000.

What advice to you give to parents of children with eczema/asthma who may have false positives from IgE testing?  My daughter's IgE numbers are off the charts, and we've been avoiding likely allergens.  The only food she's (accidently) ingested that we've avoided based on likely food allergy is cow's milk (to which she had an immediate negative reaction).

 

We've consulted 2 allergists, and both have reommended avoiding the foods she's likely allergic to until she is 5 or 6 at which time they recommened re-testing as she may have outgrown her allergies.

We're going to invite Dr. Stukus to reply to some of the questions here. He won't be able to give you medical advice, of course, but he may be able to give out general information about the issues you have brought up.

 

Eczema is a tough one to explain. I will defer that one to Dr. Stukus.

 

Regarding the MRT post, I want to take issue with your last point. One is that if RAST or skin tests are negative a child could still have an immune-mediated non-IgE mediated food allergy as is explained in the blog post above. Non-IgE mediated conditions include food protein-induced enterocolitis syndrome (FPIES), eosinophilic gastrointestinal disease (including eosinophilic esophagitis) (EGID, EoE), Heiner Syndrome and infantile proctocolitis and a couple of others.   A board certified allergist are the professionals who evaluate patients and make the diagnosis of non-IgE-mediated food allergy and should be where the patients go first for a food allergy evaluation.

 

I think it's important to differentiate between "food allergy" (IgE mediated) and "food sensitivity". Both are immune mediated reactions, but involve different mediators (chemicals). Both are reactions brought on by food and both can make you very sick, although it is the food allergy that is likely to be life threatening. Even the symptoms brought on by each can be similar. For example, abdominal pain, diarrhea,vomiting,headache,asthma,and eczema can be triggered by a food sensitivity as well as a food allergy.To make matters more confusing, an individual can have both food allergies, as well as food sensitivities. So, how does one tell the difference? While RAST and skin prick is used to detect food allergy, MRT (mediator release test) is used to detect food sensitivities. MRT is used by registered dietitians to create elimination diets tailored to individual needs. If RAST or skin prick tests are negative and it appears food is making you sick, then chances are you have a food sensitivity. OR, if you have avoided those foods to which you reacted positively on an allergy test and you still have symptoms, then you may also have a food sensitivity.

 

My daughter is now 13 and has always had belly issues.  She had skin and RAST testing done as a toddler with no indications of food allergies.  At 11 her belly isues worsened and RAST testing was redone with nujmerous positive results.  We did skin testing and she was found to be allergic to milk, egg yolk, and fish. She has what you term a Non-IgE mediated reaction.  Oncethe foods were fully eliminated from her diet her belly issues went away, she was no longer bloated and felt much better.  Based on teh article I am confused how to do a challenge on kids like my DD.  At this point we fully avoid all egg, but were hoping to try to add egg white after she is retested at her next annual visit.  But if both the skin and RAST  testing have high false rates what is the best way to do follow up testing?  Thanks in advance

Wow, that's great information thank you.  I'm just wondering what you suggest since we fall into the category of my son being tested for allergies at a young age due to his eczema; however, he never tried any of the food before. Now we have an Epi pen for him as he was diagnosed with anaphylactic allergies.  Thank you! 

Thank you for this very detailed explanation. However, I'm not sure I agree with this statement "if your child can eat a food without developing any symptoms, then they are unlikely to be allergic to that food." My son has tested negative to pretty much every allergy skin prick and blood test - only positive to hazelnuts one time and walnuts another time, both in skin prick tests. He suffered from severe eczema, head to toe, and we were looking for answers. There was no particular food that seemed to cause the eczema and he didn't suffer from any immediate allergic reactions - his eczema had developed slowly since birth. Since the allergy testing was inconclusive, we eliminated dairy, soy, gluten, some tree nuts, and corn for 30 days. His skin cleared up within days of starting the elimination diet. We added each of the foods back in slowly, each one over a four day period, and his reactions were obvious - instant itching, redness around the mouth, eczema within a few hours. With dairy he wheezes and has a mild asthma attack. Many of these are IgE mediated as you described above, I believe. So, the reason I disagree with your statement above is that it seems in some cases, if a child consumes a food they are allergic to (not anaphylactic) on a daily basis, it is possible allergy symptoms will not be obvious because the reaction is so gradual. If the food is removed completely for a given amount of time and cleared from the body, then you can see the body's true reaction to the food instantly.


I look forward to your comments.


Thank you.

Jennifer Roberge

Kids With Food Allergies
A Division of the Asthma and Allergy Foundation of America
4259 W Swamp Rd, Suite 408, Doylestown, PA 18902
Phone: 215.230.5394 | Fax: 215.340.7674
-->
×
×
×
×