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The Nutty Nature of Nuts

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For years, patients diagnosed with a tree nut or peanut allergy have been told to avoid all nuts. But what if I told you that being allergic to one nut doesn’t necessarily mean you’re allergic to another? What if I also told you that avoiding nuts altogether could result in a higher risk of BECOMING allergic to nuts?

Nuts, right?

To make things even more confusing, it’s possible to be allergic to some tree nuts and not others (e.g., a patient could be allergic to all tree nuts except hazelnut and almond). Walnuts and pecans are almost 100% cross-reactive, so if you’re allergic to one, you’re almost certainly allergic to the other. The same is true of cashews and pistachios. But that’s pretty much where the similarities end. 

Often, if a patient has an allergic reaction to a peanut or a tree nut, their allergist will advise the patient to avoid all nuts. Why? The rationale is three-fold: 1) some tree nuts are cross-reactive with others; 2) nuts are often packaged and handled in a shared facility, making cross-contact more likely; and 3) it is often easier for a doctor to advise patients to avoid all nuts (including peanuts, which are technically a legume). 

Doctors have also generally recommended strict avoidance of all nuts after a peanut or tree nut allergy diagnosis because of the challenges in distinguishing between nuts. Otherwise, the patient would be expected to know the difference between all of the different types of nuts: almonds, brazil nuts, cashews, hazelnuts, macadamia nuts, pecans, pine nuts, pistachios, and walnuts—both shelled and unshelled. Studies have also shown that allergy patients are only slightly worse at identifying tree nuts than their allergists. 

Patients would also have to trust that kitchen and waitstaff at restaurants could distinguish between the nuts (spoiler alert: many can’t). Additionally, it’s hard to find bags of tree nuts that don’t list warnings of possible cross-contact with other tree nuts or peanuts due to manufacturing practices. In order to determine which nuts a patient is allergic to and which ones are safe, one or more oral food challenges may be necessary. 

Because of this, recommending that a patient avoid all nuts has historically been deemed the more practical—and safer—approach to food allergy management. 

Then came the LEAP (Learning Early About Peanut) study.

The LEAP study suggested that kids who were at risk for developing a peanut allergy were significantly less likely to become allergic if they ate peanuts early and often. The study also showed that if a patient was unnecessarily avoiding peanuts they were more likely to become allergic to peanuts over time. This suggested that unnecessarily eliminating certain allergenic foods could increase a child’s risk of becoming allergic.

This study led to a seismic shift in the food allergy community’s understanding of food allergies and allergy management practices. Suddenly, blanket avoidance of all tree nuts and peanuts came with the potential risk of increasing an at-risk child’s chances of developing a food allergy. For this reason, it is important that allergists talk with their patients and/or the patient’s families after a peanut or tree nut diagnosis about the different approaches to managing food allergies and decide together what is in their best interest. 

The first option is the oldest approach: strict avoidance of all peanuts and tree nuts. Many patients and families feel safe with this approach. Total avoidance may lessen the fear of a reaction due to cross-contact. Accordingly, for many patients and/or families, avoidance is the right choice. Another option is to have the patient continue to avoid the foods they are allergic to (in this example certain tree nuts) and teach families how to safely eat the foods they are not allergic to. This process may involve a food challenge. Deciding to eat certain nuts when allergic to others does involve learning how to read labels to check for potential cross-contact, learning what the different nuts look like shelled and unshelled, and understanding that eating those nuts is something that should be done at home and not in restaurants. 

We still have a lot to learn about food allergies, but hopefully in time we’ll get better at managing, diagnosing, and treating them. In the meantime, for newly diagnosed food allergy patients, candid conversations are a good start. 

 

Brian Schroer, MD is on staff at Cleveland Clinic Children’s Hospital where he sees patients of all ages with allergic and food-related diseases. 

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OIT—Is It For Me?

Feeding your peanut-allergic child peanuts is not easy as a mother—I would know, I do it every day. Your instincts as a parent are to keep your child as far out of harm’s way as possible. But in today’s world, peanuts may be the best management tool we have for my peanut-allergic child.

Let me explain.

My daughter was born with a severe allergy to peanuts and tree nuts. For the first three years of her life, we strictly avoided these foods. She’s now four. Last April, we agreed to undergo an oral food challenge at her allergist’s office to find out if she was still allergic. Her peanut blood test numbers had dropped considerably—this blood test measures levels of Immunoglobulin E (IgE) to individual allergens in the body. IgE is the antibody that triggers food allergy symptoms. Plus, she hadn’t been exposed to peanut since she was a baby. Unfortunately, the oral food challenge outcome wasn’t as we hoped: after ingesting ¼ of a peanut, split into three gradually increasing doses over a 45-minute period, she experienced an anaphylactic event and we had to administer epinephrine. It was an emotional day, to say the least.

After discovering that she was still severely allergic to peanuts, we decided to explore oral immunotherapy: a method of food desensitization that involves re-introducing the immune system to the allergenic food in gradually increasing amounts over time, with the goal of eventual tolerance.

For our family, the results have been life changing. The same little girl that reacted to ¼ of a peanut now eats 12 peanuts daily with zero symptoms. But OIT is not necessarily for everyone, so I’d like to share our family’s journey and offer some insights into the process so that you can determine whether it’s a good fit for you or your child.

If your allergist doesn’t have a clear picture of your allergy severity, treatment may start with an oral food challenge. Once the individual has been identified as an OIT candidate, they are typically provided a juice-like beverage containing tiny amounts of the allergen. This beverage is consumed during the same two-hour period every day. Depending on how quickly a patient builds up a tolerance, your allergist may recommend coming in every week or two for an “updose”—an increase in the amount of allergen consumed. As the immune system grows more tolerant, the patient eventually moves to a powder form (which is typically sprinkled onto food), and finally to solids (e.g., whole nuts).

Importantly, OIT requires a considerable time commitment. Although updosing typically occurs every week or two, the allergen must be consumed every day to build and maintain tolerance. OIT also places constraints on physical activity. During OIT, the patient can only engage in calm, quiet activity half an hour before dosing, and at least two hours afterwards (during their observation period). This ensures that the immune system doesn’t get “revved up” unnecessarily and trigger an allergic reaction.

Is OIT perfect? Not quite. For the foreseeable future, my daughter must eat 12 peanuts with a two-hour observation period everyday. However, we can now choose the time frame each day, and expect the observation period to shorten over time. There’s also a measure of unpredictability. On two occasions, our daughter developed a couple hives after her prescribed dose, and we had to give her antihistamines. Other times, we had to lower her dose because she was sick, which can compromise the immune system. It is these situations, and the risk of producing a more serious adverse outcome, that discourages many allergists from taking up the practice. Indeed, OIT is still relatively controversial. Additionally, OIT treatments are still in their nascent stages and are not widely practiced, so there is less data and information available.

Importantly, not every food-allergic child or adult is a good candidate for OIT. For example, if a patient has severe environmental allergies, acute asthma, or eosinophilic esophagitis, they will not likely qualify for OIT. Additionally, OIT treatment is not available for all allergens—desensitization to peanuts, for example, is far more common practice than, say, shellfish.

If you think OIT may be of interest to your family, I’d encourage you to talk to your allergist and seek out additional information and guidance. You can also reach out to me at mnohe@allergyamulet.com for more on the parent perspective—I’m always up for a good food allergy chat!

- Meg, Director of Strategic Development

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