Q:

4/19/2012
An 8 year old patient of this practice is being treated for Eosinophilic Esophagitis. His GI doctor has prescribed Nexium. Our allergy office performed food testing- milk skin testing was negative but CAP-RAST was also done to milk and many other foods. The only positive results were Milk with a level of 6.95 kU/L (a negative result is usually <0.35) and incidentally done was beef with a level of 5.11 kU/L. Is there a RAST level noted in recent research which would indicate the level in which one becomes more concerned about the beef? His symptoms include diarrhea, vomiting at times and GERD but not necessarily when the above foods are ingested. He is following a milk free diet at this time and will be followed up with by his GI doctor who isn't particularly concerned about his milk RAST level and had encouraged it to be back in his diet even though this office has encouraged strict avoidance. Any input you can provide on this subject would be greatly appreciated.

A:

Thank you for your inquiry.

First of all, I think that it would be very helpful to you and the physician with whom you work, should you be treating patients with eosinophilic esophagitis, to become familiar with a very important, fairly recent article, dealing with the diagnosis and management of this condition.

There is no definitive answer to your questions, and there are a number of subtle nuances to be considered whenever one deals with the presence of positive skin tests in patients with eosinophilic esophagitis. These issues are discussed in detail in this article. The article should be readily available to you and the physician with whom you work. It is entitled "Eosinophilic Esophagitis: Updated Consensus Recommendations for Children and Adults," published in The Journal of Allergy and Clinical Immunology, Volume 128, Issue 1, Page 320, July, 2011.

The article summarizes all recent data and consensus opinions regarding the issue of testing for foods and eosinophilic esophagitis, and the application of dietary therapy based on these tests.

With that preamble, I will try and address the inquiry you posed regarding your patient. Unfortunately, there are no quantitative data regarding ImmunoCap levels specifically related to the likelihood that a given food will adversely affect a patient with eosinophilic esophagitis. Therefore the only quantitative information that we have relating ImmunoCap levels (and skin tests as well) is based upon the likelihood of foods demonstrating a given ImmunoCap level or skin test size having a positive oral food challenge. I think you are aware of these data for milk. Unfortunately there are no data in regards to beef.

The only information that we have therefore to draw on is the ImmunoCap data from milk which shows that a level of 32 correlates with a 95% chance of reacting to milk on oral challenge. An ImmunoCap value of 32 correlates with a 90% chance of having a positive oral challenge to milk. On the other hand, an ImmunoCap value of less than 0.8 is associated with a 95% chance of a negative oral challenge, and an ImmunoCap value of 1.0 is associated with a greater than 90% chance of a negative oral challenge (1, 2).

However, this, as noted above, refers to responses to food challenge and has not been studied in regards to the same levels causing flares of eosinophilic esophagitis in patients suffering with this condition.

But based upon this level, one can see that there would be the possibility, but more than likely a distant one, that your patient would be adversely affected by the ingestion of beef or milk.

There are ways that you could get a better sense of whether this could occur. One thing you could do, if it has not been done, is define whether or not your patient is atopic. That is, does he have a number of different positive epicutaneous tests to aeroallergens? Does he suffer from any other allergic disease (atopic dermatitis, allergic rhinitis, or asthma)? The likelihood of these levels of ImmunoCap being significant in your patient would rise if he was atopic, and these levels would be less likely to cause problems if he was not atopic.

It must be remembered that a very significant percentage of cases of eosinophilic esophagitis occur in nonatopic individuals who have no allergy whatsoever, food or otherwise, and even in atopic individuals with eosinophilic esophagitis, food allergy is not universal.

But, probably the most effective way to discern whether or not these tests are of significance is to do a graded oral food challenge. This would not be 100% accurate because there is no information that says a positive oral challenge correlates with the ability of the food to produce exacerbations in eosinophilic esophagitis, but if there was a positive food challenge, you would have strong indication to leave these foods out of the diet. If not, although you could not guarantee they would not flare eosinophilic esophagitis, the odds would be less likely of this occurring.

Also, I think it is important for you to consider whether or not to treat this child with swallowed inhaled corticosteroids (e.g., fluticasone). The indication for the administration of this agent are discussed in detail in the consensus guidelines referenced above, and I would suggest you at least consider this therapy if the child does not do well.

In summary, there is no definitive answer to your question, but you should try and do the following:

Discern whether or not this child is atopic.
Consider an oral food challenge.
Also consider, if he is not doing well, the use of swallowed inhaled corticosteroids.

In closing, again, I think that the consensus guidelines article noted above would be very helpful to you and to the physician with whom you work if you are continuing to see patients with eosinophilic esophagitis because the questions that you posed will continue to arise involving different foods and consideration as to whether or not to begin swallowed inhaled corticosteroid treatment.

Thank you again for your inquiry and we hope this response is helpful to you.

References:
1)Sampson and Ho J Allergy Clin Immunol 1997;100:444-5
2)Lack G. NEJM 2008;359:1252-60

Sincerely,
Phil Lieberman, M.D.

 

Erratum:
If you read this response before April 26, the figure 23 kIU cited for 95% predictive value for oral challenge to milk is in error.  It should have read, in the above response, 32 kIU. The number has since been corrected.

Erratum:
This erratum cites a more recent cut-off point for a 95% predictive value for milk that replaces the 32 kUA value cited in our response. The more recent cut-off point is 15 kUA/L. (Sampson, H: Utility of Food-Specific IgE Concentrations in Predicting Symptomatic Food Allergy - The Journal of Allergy and Clinical Immunology 2001; 107:891-896.)

We received the following comment regarding your "Ask the Expert" inquiry from 4/19/12 and our response:  
 
"My question is regarding the 4/19/12 inquiry regarding EE and the immunocap values for milk and beef. Do you think pointing out the 10% sensitization to beef in milk sensitive patients would have been helpful for this physician in trying to make a clinical decision in this particular situation?"
 
The above comment is appropriate and we are posting it as an addendum.  
 
Thank you again.
 
Sincerely,
Phil Lieberman, M.D.

AAAAI - American Academy of Allergy Asthma & Immunology