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Ask Stanford Med: Pediatric immunologist answers your questions about food allergy research

Ask Stanford Med: Pediatric immunologist answers your questions about food allergy research

Food allergies affect millions of children, who find it difficult to enjoy ordinary activities like birthday parties and restaurant meals because of worries that something they eat could send them into anaphylactic shock. As the New York Times described recently, Stanford scientist Kari Nadeau, MD, PhD, is studying how to desensitize children to their allergy triggers. Here on Scope, she recently took questions on food allergies and her desensitization research.

Many readers asked how they could enroll in Nadeau’s research or in similar allergy treatment trials near their homes. Information for prospective study subjects around the world is available here; enter “food allergy” in the “Search for Studies” field, and after searching, click the “On a Map” tab to see trials grouped by location. For those who live near Stanford, go here for details on participating in Nadeau’s research.

Below are Nadeau’s responses to a selection of questions submitted using the hashtag #AskSUMed the comments section on Scope. As a reminder, Nadeau’s answers are meant to offer medical information, not medical advice. They’re not meant to replace the evaluation and determination of your doctor, who will address your specific medical needs and can make a diagnosis and provide appropriate care.

@vikas_aditya asks: What’s the simplest way to identify the cause of an allergy in kids?

If you suspect an allergy to a specific food or environmental cause, skin prick testing is the simplest and least invasive way to initially identify the allergy but it is not the gold standard. A food challenge in the doctor’s office is the true way to test for food allergies.

Elizabeth P. asks: Is there anyone working to find the exact cause of why so many children, teens and adults are developing life-threatening food allergies today? On a related note, @ceband asks: What do you think of the theory that altered gut microbiomes have led to the rise in allergies and autoimmune disease?

Many scientists and researchers are trying to understand the rising prevalence of food allergies in children. Though there are many theories regarding the increase in this prevalence, we still lack definitive answers. Hypotheses have focused on hygiene, dietary fat, antioxidants, vitamin D and dual-allergen-exposure. Altered gut microbiomes might play a role. It does not appear that genetically modified foods are directly linked to food allergies.

Julie Barnes asks: I am currently pregnant and am wondering if I will possibly be creating a food allergy in my unborn child if I avoid all dairy and egg while pregnant and breastfeeding.

There is recent evidence that a diet in pregnancy and during breastfeeding that is high in Vitamin D, follows features of a Mediterranean diet and includes probiotics may be helpful to prevent asthma and allergies. And a healthy, balanced diet is important to your overall health and the health of your baby. However, we do not have evidence that mothers will create food allergies by food avoidance in pregnancy or breasfeeding. Similarly, there is no evidence from the general population that mothers can create food allergies by eating certain foods during pregnancy or breastfeeding.

Wing-Yee Fu asks: Can adults develop sensitivities if they don’t eat certain food groups for a period of time? I have noticed that I develop hives when I ingest dairy and soy, when in the past I am not allergic.

It is uncommon to develop a true allergy to a food that you previously ate and tolerated. However, if you think you have developed a new food allergy, please go see an allergy specialist.

Clara Luu asks: What do you know about food allergies and certain types of skin conditions? Do lots of people have mild food allergies that cause common conditions such as irritable skin? On a related note, Hilary Paterson asks: My 3-year-old daughter is allergic to peanuts. She has had eczema since she was a small baby. It used to be quite severe but has almost disappeared. Is this a sign that her allergy could be weakening, or simply because she has not had any peanut products since her diagnosis?

The term atopy refers to a predisposition toward developing certain allergic hypersensitivity reactions. A person with atopy usually presents with one or more of the following: eczema (atopic dermatitis), allergic rhinitis (hay fever), allergic conjunctivitis, or allergic asthma. Patients with atopy have a tendency to have food allergies.

Hilary, a baby’s eczema often improves with age; however, I would NOT assume that her peanut allergy has also weakened. The only way to accurately diagnose the current state of her peanut allergy is to do a food challenge in a doctor’s office.

Karen moloney asks: My son has allergies to milk, eggs, nuts, tree nuts and sesame seeds as well as asthma and inhalant allergens. What are your thoughts on Vitamin D and probiotics?

There is recent evidence suggesting that during pregnancy and breastfeeding, a diet high in Vitamin D and probiotics may be helpful in preventing the development of asthma and allergies. However, Vitamin D and probiotics have not been shown to alter the course of existing food allergies.

Monica Frazier asks: Is there any precedence for desensitization therapy for non-immunoglobin E mediated allergies, like Food Protein-Induced Enterocolitis Syndrome?

Food allergen desensitization has not been utilized as a therapeutic modality for the management of food protein-induced enterocolitis syndrome, food protein-induced allergic proctocolitis, or food protein-induced enteropathy syndrome.

Alison asks: What about children who have strong immunoglobulin-E (IgE) reactions (confirmed severe allergic reactions, and not just high IgE levels) to most foods as well as severe Eosinophilic disorders (EGE in our case)? Are there any studies or research being done for these cross-over kids?

Although the pathogenesis and immune basis of IgE-mediated food allergic disorders and eosinophilic gastrointestinal diseases (EGIDs) is understood to be different, food allergens are relevant in both disorders. Specific IgE testing, and skin prick testing to food allergens play a central role in identifying IgE-mediated food allergies. These tests are also used to identify potentially relevant foods in EGIDs and in designing an elimination diet. Although food allergen desensitization is being studied for the management of IgE-mediated food allergies, it is not being utilized for management of EGIDs. At this time, research efforts have focused on studying these 2 disease entities separately.

Sanda Preuett-Shea asks: Are there any longitudinal studies on animals using oral immunotherapy? What is the longest study on humans and oral immunotherapy?

No, there have not been any longitudinal studies in animals. The longest study of oral immunotherapy in humans is about three years.

Sarah Foote, Leslie Olsen, Anne, Veronique P and Jodi Pritchett ask: What about age restrictions for participants in your research? Are the trials are open to very young children, adults and the elderly?

The Nadeau lab has several ongoing studies. The age requirements differ depending on the study. Certain trials will be available for really young children, and also for adults and elderly patients.

Laura asks: If the [current multi-allergy] study is a success, how long would it take for the FDA to approve this as a standardized treatment? On a related note, Stephanie C asks: Will time have run out for non-pediatric allergy patients by the time this is finally approved for widespread treatment? Is there a window of effectiveness in different age groups?

If studies on food allergen desensitization continue to yield promising results, one estimate is that it might take over 10 years for the FDA to approve this treatment as standardized therapy. At this stage there is no data strongly suggesting that food allergen desensitization only works in the pediatric population. Food allergen desensitization studies have shown benefit in both pediatric and adult subjects. Further research will need to be conducted to better understand differences in the efficacy of food allergen desensitization in different age groups.

Previously: Ask Stanford Med: Pediatric immunologist taking questions on children’s food allergy research, A mom’s perspective on a food allergy trial and Searching for a cure for pediatric food allergies
Photo by michelle@TNS

9 Responses to “ Ask Stanford Med: Pediatric immunologist answers your questions about food allergy research ”

  1. ZRA Says:

    The link to the studies/trials around the world is not working. Please fix.

  2. myriam doherty Says:

    Hello

    I am writing from Ireland and tryingto access your link on this page to centres around the world doing food allergy trials. I have a 4 year old son allergic to sesame and nut and we would like to enrol him.

    Can you help?

    Thank you
    Myriam

  3. Michelle Brandt Says:

    ZRA, that link has been fixed. Thanks for letting us know.
    -Michelle (editor)

  4. LCondrey Says:

    Dr Nadeau,

    Is it possible for other allergists to also conduct similar trials before the FDA approval?

    I have read a lot about your trials with peanuts and tree nuts. Do you think this would scale over to other food groups like shellfish and eggs?

    Thanks!

  5. vinu Says:

    “In 1913, he (Charles Richet) was awarded the Nobel Prize for his researches on anaphylaxis. He invented this word to designate the sensitivity developed by an organism after it had been given a parenteral injection of a colloid or protein substance or a toxin (1902).”

    http://www.nobelprize.org/nobel_prizes/medicine/laureates/1913/richet-bio.html

    It is a well known fact that vaccines contain egg, casein (milk protein), yeast and soy proteins (http://www.cdc.gov/vaccines/vac-gen/additives.htm).

    I have learnt that agar (red seaweed derived) is used in the manufacture of many vaccines and injections. Red algae/seaweed can contaminate any sea food. That can explain allergies to sea foods.

    I have learnt that Vitamin K1 injections are given to newborns. Vitamin K1 injections contain fatty acids ( vegetable oils that could be from tree nuts, soy, peanuts …).

    Dr. Thomas Platts-Mills of the University of Virginia discovered that alpha-gal injected into humans by tick bites results in sensitization to alpha-gal. Since red meat contains alpha-gal, tick bite victims develop red meat allergy.

    Just about every food allergy seems to be linked to food proteins parenterally administered by vaccines or injections (or even tick bites). With millions affected by the food allergy epidemic, it seems we are still injecting children with vaccines/injections containing food proteins without thorough research on the matter?

    On a related note, pancreatic digest (of unknown mammalian origin?) and human diploid lung fibroblasts are also used in the manufacture of vaccines. The same sensitization mechanism could result in auto immune disorders such as diabetes and asthma?

    The Mechanism of sensitization

    Food (plant and animal) proteins such as egg, milk (casein), yeast, gelatin, red seaweed (agar) are present in various vaccines (CDC’s vaccine ingredients list). When food proteins are injected in to the blood stream during vaccination, a type I hypersensitivity reaction against an allergen, encountered for the first time, causes a response in a type of immune cell called a TH2 lymphocyte, which belongs to a subset of T cells that produce a cytokine called interleukin-4 (IL-4). These TH2 cells interact with other lymphocytes called B cells, whose role is the production of antibodies. Coupled with signals provided by IL-4, this interaction stimulates the B cell to begin production of a large amount of a particular type of antibody known as IgE that are specific to the food proteins. Secreted IgE circulates in the blood and binds to an IgE-specific receptor (a kind of Fc receptor called FcεRI) on the surface of other kinds of immune cells called mast cells and basophils, which are both involved in the acute inflammatory response. The IgE-coated cells, at this stage are sensitized to the allergen (food proteins). [1] [2]

    Mast cells and basophils are found in large numbers in and around the mouth. These locations are prone to injury and thus need more protection against infection. These mast cells and basophils are now IgE-coated and primed to react to the food proteins.

    If the vaccinated person now eats these foods, the food proteins bind to the IgE molecules held on the surface of the mast cells or basophils in the mouth. Cross-linking of the IgE and Fc receptors occurs when more than one IgE-receptor complex interacts with the same food allergenic molecule, and activates the sensitized cell. Activated mast cells and basophils undergo a process called degranulation, during which they release histamine and other inflammatory chemical mediators (cytokines, interleukins, leukotrienes, and prostaglandins) from their granules into the surrounding tissue causing several systemic effects, such as vasodilation, mucous secretion, nerve stimulation and smooth muscle contraction. This results in rhinorrhea, itchiness, dyspnea, and anaphylaxis. Depending on the individual, the allergen, and the mode of introduction, the symptoms can be system-wide (classical anaphylaxis), or localized to particular body systems; asthma is localized to the respiratory system and eczema is localized to the dermis.[2]

    In other words, an allergic reaction occurs to the foods that contain the food proteins which were present in the vaccine or injection.

    ” …. i have often heard people dismiss the widespread experimental model of allergy, in which BALB/c mice are injected IP with ovalbumin in alum (the most common adjuvant in vaccines for humans) and then later challenged orally or nasally with OVA. the dismissal is usually based on a statement that goes something like “but this isn’t the way that humans are sensitized to allergens”.

    well……perhaps, at least in some cases, it IS how humans are sensitized to allergens? perhaps not by intraperitoneal injections, but nevertheless by injections? sometimes by needles (containing alum); sometimes by insects; perhaps sometimes by injuries (thorns? nails? cuts?)….” – Dr. Matzinger at the National Institute of Allergy and Infectious Diseases.

    You can see Dr.Matzinger’s full response here:

    https://list.nih.gov/cgi-bin/wa.exe?A2=ind1305&L=immuni-l&F=&S=&P=37286

  6. Querida Says:

    Hi
    I’ve has servier allergies all my life and would love to find out more about your trials. I have anaphalaxis to cows milk and eggs and react badly to wasps stings.

    I would love to know if there is a simular process or treatment for adults that have had servier allergies all their lives.

    Many Thanks
    Querida Ross

  7. Nikki Says:

    Dear Dr Nadeau

    It was with great interest that my husband and I watched a 60 Minutes story last night about your clinical trial. The young girl featured in the story had an amazing result based on your work. We live in Australia, our 2.5 year old son is allergic to peanuts, cashew & pistachio nuts, eggs, dairy, wheat (possibly gluten), rockmelon, banana at this point in time. Our dream is for him to one day be allergy free and safe and healthy in his everyday life. Our question is do you have anyone that you are working with in Australia regarding your clinical trials? We would dearly love to speak with them.
    Many thanks for your time.
    Nikki

  8. Louisa Oneill Says:

    Hi your program was featured on 60 minutes in Australia. Is the allergy treatment available in Australia.? You also didn,t mention adults with allergys. My son who is 36yrs is allergic to dairy, gluten, rice, zanthan gum and salicylates in fruits. If he has any of those foods, it not only make him very sick but also alters his moods and becomes extremely depressed.
    Regards Louisa

  9. Leigh Says:

    Hi I too watched the 60 mins episode that featured your treatment methods and I wondered if this same method could be used to treat coeliac disease? My 6 year old daughter is a sufferer and while it’s manageable, we’d/she’d be interested in exploring alternatives to this life.

    Leigh

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