By Dr. Paul Ehrlich
A year ago I wrote a response to a Pediatrics study that seemed to claim black children were at higher risk of food allergies than non-white kids. The WebMD account said, “The study found that African-Americans have a threefold higher risk for food allergies than the general population and that African-American male children had the highest food allergy rates in the U.S., with a fourfold higher risk.” I wrote, “Funny, but after spending at least one day a week for several years in inner-city schools dealing with severely asthmatic children, I saw NO co-morbidity with peanut allergies, which led the Pediatrics list.”
A new article in the Journal of Allergy and Clinical Immunology (JACI) sheds light on this subject that lends credence to both sides, although I must say that it lends more support to my observations than it does to assertions of risk levels. The most important thing it does, however, is provide more ammunition against the methods by which food allergies are generally diagnosed.
Drawing partly on that same Pediatrics study from a year ago, the authors of the new JACI article say, [B]lack participants had significantly higher median values for total IgE, peanut-specific IgE, and hen’s egg white–specific IgE compared with white participants. These findings suggest that black participants might have a higher level of allergic reactivity than white participants.”
Does this indicate a hidden epidemic or an epidemic waiting to happen?
Not according to these authors. “We demonstrate that in a population of high-risk atopic children, black race increases the risk of sensitization as measured based on specific IgE levels but is paradoxically associated with a decreased risk of sensitization to peanut, as measured based on SPT responses, and a decreased risk of likely clinical reactivity to peanut (a wheal diameter >4 mm is defined in our study as likely clinical PA at this age)… This might reflect an evolutionary adaptation toward TH2 responses in the face of high rates of infection with helminths [parasites common in their ancestral homes]. Another possibility is that IgE in black infants is directed against different allergens compared with that in white children or to different epitopes within those allergens. However, it is also possible that this difference between white and black children might not have been observed with other prescreening criteria.”
Okay. I was right. But I’m not going to do an end-zone dance. 
Double Dutch by nycitysnaps.com
Food challenge by clinicaladvisor.com
I read that repeatedly, and understand, that the “gold standard” for diagnosing a food allergy is the DBPCFC, but would you actually suggest that to someone in this scenario?
My daughter is now 4 years old, with asthma that I still don’t feel is completely under control. When she was 18 months old, her sIgE for Whole Peanut was 95.6 kUA/L. At around 3 1/2 years of age, her whole peanut value (from a different lab) was 57.3 and her Ara h2 was 31.8.
I know you cannot give *me” specific medical advice, but can you discuss the issue, in general? Would a physician really suggest a DBPCFC with numbers like that? She has never ingested peanut, directly, to my knowledge, but it seems like pure madness to willfully expose her to peanut just for a “gold standard” confirmation, when the numbers are pretty convincing.
She has other food allergies, as well, to which she has had anaphylactic reactions, so I know she is capable of severe allergic reactions. The IgE values for those foods is lower than that of peanut, and even though I know the numbers are not to be compared in that way, it certainly causes me concern that her peanut reaction would be even more severe than those I’ve seen from cow’s milk and flax seed.
Dear Selena,
Thanks very much for writing.
We always say that a combination of tests and a detailed clinical history can be indicative of a real food allergy. Just because DBPCFC amounts to a gold standard and an oral food challenge (OFC) a silver standard doesn’t mean they have to be done in a case where the numbers are high and there is a verified history of allergic disease. As I said in an earlier post, “An OFC is not a screening tool. It is there to confirm an allergist’s clinical judgment based on a thorough history, other test results, and years of training.” I usually recommend an OFC when there has been incidental ingestion of a previously diagnosed food allergen with no effect, or when someone has high allergen-specific IgE but demonstrated tolerance to that food.
Furthermore, in light of the fact that your child has asthma, I think you have to be very careful. The worst anaphylactic reactions are often in people who also have asthma because their airways are already inflamed and likely to react.
Dr. Paul Ehrlich
Thank you very much for your response! I agree that my daughter’s asthma literally gives her less “breathing room” in the event of a serious allergic reaction, which is why I’m trying to get it under control.