Hazelnut allergy

By Symon, Every Label · June 30, 2026

Hazelnut allergy is an IgE-mediated immune reaction to the seed proteins in Corylus avellana, the hazel tree, and it is the most common tree-nut allergy in Europe. In plain terms: your child’s immune system reads certain hazelnut proteins as a threat, and a reaction can run from an itchy mouth to a whole-body allergic reaction that affects breathing and blood pressure, called anaphylaxis. It is a true allergy, not a sensitivity or an intolerance. About 1 percent of European schoolchildren have doctor-diagnosed hazelnut allergy (Lyons 2020). What sets hazelnut apart from most food allergies is that how serious it tends to be depends heavily on which hazelnut protein your child reacts to, which is why one specific test, described below, is worth asking for by name.

If your child was just diagnosed, read this first.

This page is long on purpose. It is also the page you will come back to for years. You do not need all of it today. This week, this is what matters:

• Carry two epinephrine auto-injectors everywhere your child goes, and learn the few signs that mean use one now. That is the section to read tonight (Emergency preparedness, below). If you do not have the prescription yet, that is the first call to your allergist or pediatrician.
• Read every label, every time. The words to catch are hazelnut, filbert, cobnut, and the words that hide it: gianduja, praline, and Nutella-style chocolate spreads (Reading labels, below).
• With hazelnut more than most allergies, the component test tells you a lot. There is a serious kind and a milder kind, and one blood test sorts them. Ask your allergist about Cor a 14 (the serious marker) and Cor a 1 (the milder, birch-linked one) by name (Components, below).
• Walnut and pecan often travel with hazelnut. Treat them as a tested question, not an automatic yes and not an automatic no (Cross-reactivity, below).
• Almond is different: it is the least cross-reactive tree nut, so do not drop almond on a hazelnut allergy alone. Test it rather than assuming (Cross-reactivity, below).
• You do not have to understand the protein science to keep your child safe. The components and the test numbers are for unhurried conversations with your allergist.

Everything else here is waiting for you, in roughly the order the questions tend to come up. Read it when you want it.

Where a fact below is clinical, it carries its source. None of it is a substitute for your allergist.

What hazelnut allergy is, and who has it

Hazelnut allergy is an IgE-mediated immediate-type food allergy, and hazelnut is the most common tree-nut allergy in Europe (Datema 2015, Lyons 2020). When your child eats hazelnut, IgE antibodies on their immune cells latch onto the hazelnut proteins and trigger a release of histamine and other chemicals within minutes. That release is the reaction. The reason for everything practical on this page, the auto-injectors, the label habit, the written plan, is that the same allergy that shows up as an itchy mouth in one child can be whole-body in another, and which one it is comes down to the proteins.

Hazelnut is a true tree nut, in the plant family Betulaceae, the birch family. That family link is not trivia: it is why hazelnut is the textbook example of a food allergy that can be driven by birch pollen. A child who is allergic to birch pollen can react to hazelnut because one hazelnut protein looks, to the immune system, like a birch protein. That birch-linked form tends to be the milder, itchy-mouth kind. A different set of hazelnut proteins, the storage proteins, drives the serious, whole-body kind. The components section is where that split becomes the most useful thing on the page.

About 1 percent of European schoolchildren have doctor-diagnosed hazelnut allergy (Lyons 2020, the EuroPrevall and iFAAM school-age surveys). A clean hazelnut-specific figure for US children is not available, because US data are usually reported for tree nuts in aggregate rather than hazelnut alone. Onset is usually early childhood, and in young children the allergy is more often the serious storage-protein kind, while in adults the milder birch-linked kind predominates (Datema 2015).

Diagnosis combines your child’s history with testing, and for hazelnut the testing has one high-value move worth knowing about. The next section is what it is.

The components that drive severity

Hazelnut is not one thing to the immune system. It is a handful of proteins, and which one your child reacts to changes how serious the allergy tends to be, more so for hazelnut than for almost any other food. The good news is that one blood test sorts it, and asking for it by name is the highest-value thing you can do.

A standard hazelnut test (the skin prick, or the basic blood test) only tells you the immune system has noticed hazelnut at all. A more detailed test, component testing, breaks that down protein by protein. It answers the question you actually care about: is this the serious, whole-body kind, or the milder, itchy-mouth kind? For hazelnut, two results carry the weight:

• The kind that can turn serious is the protein your allergist calls Cor a 14 (with its partner, Cor a 9). These are the heat-stable storage proteins. A child who reacts to these has the kind of allergy that can go whole-body, and roasting does not make the nut safe, so this is the result that matters most.
• The kind that is usually milder is Cor a 1. This is the birch-pollen-linked protein. If your child’s positivity is mostly to Cor a 1, that often points to the birch-driven, itchy-mouth pattern that tends not to progress to anaphylaxis. It does not, on its own, tell you a food is safe to eat, and the decision to try any form of hazelnut stays with your allergist, but it reframes a scary-looking positive test.

So the high-value move is simple: ask your allergist to run component testing and to measure Cor a 14, Cor a 9, and Cor a 1, not just whole-hazelnut IgE, and ask what the pattern means for severity. You do not need to learn the protein names or the lab numbers yourself. They are below, written so the words on your child’s lab report mean something when you want them to.

Cross-reactivity, real and cautionary

The honest version of this section leads with what changes the plate, not with a reassurance. For hazelnut, the part that matters most is that a positive storage-protein result is a red flag, and that two other tree nuts travel with hazelnut closely enough to test rather than assume.

A positive storage-protein test is a red flag, not a minor finding. A positive test to a tree-nut storage protein, hazelnut Cor a 9 and Cor a 14, and the same class in cashew, walnut, and pecan, points to the whole-body kind of reaction, not a low-risk one. These proteins are heat-stable and survive digestion, so roasting, baking, or cooking does not make the nut safe. Treat a positive as a reason for strict avoidance and an epinephrine plan, and confirm any tolerance only with an allergist.

Walnut and pecan travel with hazelnut. Hazelnut, walnut, and pecan allergies frequently occur together, and hazelnut cross-reacts with walnut and pecan through their shared seed-storage proteins, the 2S albumins and legumins. A child with a primary hazelnut allergy and storage-protein sensitization is at real risk for walnut and pecan too. This is a tested question your allergist works through, nut by nut, not an automatic shared diagnosis, but it is the direction to expect.

Almond is the opposite case, so do not over-avoid it. Almond is the least cross-reactive of the common tree nuts, and most people who test positive to almond actually tolerate it. A positive almond test, or a hazelnut allergy on its own, is not a reason to drop almond. Ask for component testing or a supervised challenge rather than removing it on assumption.

The birch-pollen link, and what we cannot yet reassure you about. Many hazelnut-allergic people, especially adults, are sensitized to hazelnut through birch pollen, and that birch-linked form is often the milder, itchy-mouth oral allergy syndrome (Datema 2015). It is a real and common pattern. But whether a particular child can safely eat any form of hazelnut, including roasted hazelnut in baked goods, is not something this page will tell you. The birch-linked protein, Cor a 1, is partly broken down by roasting, which is why some birch-driven children tolerate roasted hazelnut, but a child sensitized to the storage proteins is not protected by cooking at all (Pfeifer 2015), and a blood test does not tell the two apart on its own. So the eat-or-avoid call, and any challenge, is your allergist’s, not a rule you can read off the component panel.

The one cleared reassurance: coconut. Coconut, despite the name and the labeling rule, is botanically a fruit, not a tree nut, and most tree-nut-allergic people tolerate it. Coconut is usually a yes, confirmed with your allergist.

Hidden sources

Hazelnut hides in more places than most tree nuts, because of European chocolate and confectionery. These are worth a one-time read now; after that you will spot them on your own, and the full label-scanning guide is on where hazelnut hides.

Chocolate and confectionery. European chocolate confections are commonly hazelnut-based: Nutella (hazelnuts are 13 percent on the EU label), Ferrero Rocher, Baci, gianduja and praline fillings, and Frangelico liqueur. Note that European praline is usually hazelnut, which is different from US praline, which is usually pecan. On European children’s menus, crepes and pastries are often Nutella-filled by default, so ask.

Cosmetic and skin-care oil. Cold-pressed hazelnut oil, listed on an ingredient panel as “Corylus avellana seed oil,” appears in some facial oils, lip balms, and skincare and is a documented contact-urticaria risk for hazelnut-allergic people. Scan the INCI list for “Corylus avellana” rather than relying on a brand name, since formulations vary by line and region.

Coffee shops and bakeries. Do not assume “hazelnut flavour” means nut-free. Many hazelnut coffee syrups are synthetic, but not all, and some brands declare hazelnut. The only reliable way to know is to read that product’s allergen statement or ask the barista or manufacturer. Shared grinders on flavoured beans, bulk bins, and shared bakery counters are real cross-contact risks regardless of the syrup.

The label words that do not say “hazelnut.” Gianduja (chocolate-hazelnut paste) and European praline both mean hazelnut without containing the word, and “natural flavor” can occasionally mask it. The reading-labels section below has the full scan list, and where hazelnut hides has the complete lexicon.

How exposure actually happens

The routes parents fear most are usually not the ones that cause serious reactions. Eating hazelnut is. The rest are lower-risk than they feel, with a couple of specific exceptions.

Eating it (high). Swallowing hazelnut protein is the route that causes whole-body reactions. Everything else is far behind it. Cooking does not help when the storage proteins are involved: Cor a 9 and Cor a 14 are heat-stable, so roasted or baked hazelnut stays allergenic for a storage-protein-sensitized child (Pfeifer 2015).

Skin contact (moderate, higher with eczema). Hazelnut on intact skin usually causes at most a local reaction. The real exception is broken or eczematous skin, where the risk is meaningfully higher, and cold-pressed hazelnut oil in cosmetics is the documented contact-urticaria route (see Hidden sources).

Breathing it in (low). Hazelnut is not volatile the way shellfish cooking aerosols are, so ambient smell is low-risk. Bulk-processing or occupational dust is the uncommon exception.

Pollen, the hazelnut-specific route. Hazelnut is unusual in that sensitization can come through the air, by way of birch pollen and the early-spring hazel pollen itself, not only through eating (Datema 2015). This is the mechanism behind the milder birch-linked form, and it is why the allergy sometimes appears alongside spring hay fever.

If your child is in hazelnut immunotherapy, one note: the risk levels above describe ordinary life outside active treatment. During active OIT build-up, the risk from an incidental exposure is modulated, and the treatment section is where that is explained.

Reading labels

This is the habit that does the most day-to-day work, and it gets fast. The words to scan for are hazelnut, filbert, cobnut, and on cosmetics “Corylus avellana seed oil.” In the US, tree nuts including hazelnut must be declared by their specific name under FALCPA, and the EU requires hazelnut to be named under Regulation 1169/2011 (FALCPA, effective 2006; EU 1169, applying since 2014).

A few terms hide hazelnut without naming it, and they are the ones to learn: gianduja (chocolate-hazelnut paste), praline (European praline is hazelnut-based, unlike US pecan praline), and any Nutella-style chocolate spread. “Natural flavor” can occasionally mask hazelnut where ingredient rules are loose. When a term is unclear and the manufacturer will not say, treat it as a reason to call the company, not a reason to assume it is safe. The full label guide is on where hazelnut hides.

Then there are the precautionary labels: “may contain nuts,” “may contain hazelnut,” “made in a facility that also processes tree nuts.” These are voluntary and unregulated in both the US and the EU, so they are not a reliable measure of how much risk is actually present. How strictly you treat them is a personal call along a spectrum, weighing a real but variable cross-contact risk against ruling out a large share of the grocery store. This page will not pick that threshold for you.

Severity, and what predicts a bad reaction

The strongest population-level predictor of a severe hazelnut reaction is sensitization to the storage proteins Cor a 14 and Cor a 9, the proteins from the components section (Datema 2015, Caffarelli 2021). Isolated sensitization to the birch-linked Cor a 1 points the other way, toward the milder oral allergy syndrome pattern, and the lipid-transfer-protein pattern (Cor a 8) is the cofactor-sensitive one, where exercise, NSAID pain relievers, alcohol, or an empty stomach can lower the threshold on a given day. A history of a previous severe reaction is the next strongest input after the component pattern.

Here is the part that justifies always carrying epinephrine. The size of the last reaction does not reliably predict the next one, and a positive storage-protein test is a red flag even if reactions so far have been mild. A child whose only reaction so far was an itchy mouth can still have anaphylaxis next time, especially if the storage proteins are involved. That is not a reason to live in fear; it is the single reason the auto-injector travels everywhere.

These thresholds are for the unmodified case. The component figures above describe a hazelnut-allergic child who is not in active oral immunotherapy. During active hazelnut OIT build-up, the dose that can set off an incidental reaction is modulated, often downward, so the numbers here are the baseline and active treatment shifts them. Treatment options, below, is the home for that.

Emergency preparedness

Hazelnut anaphylaxis is treated epinephrine-first. Epinephrine is the first-line treatment for a severe reaction, not an antihistamine and not a wait-and-see. If you see anaphylaxis, you give epinephrine and then you call emergency services.

The signs that mean epinephrine now include any two body systems reacting at once (for example hives plus vomiting), or any single severe sign on its own: trouble breathing, throat tightness, a hoarse or weak cry, repetitive coughing, pale or floppy appearance, or a sense of impending doom in a child old enough to say so. When you are unsure, the guidance is to give epinephrine, because the danger of withholding it in a true reaction is far greater than the danger of giving it when it turns out you did not need to.

After giving epinephrine, call emergency services and lay the child down with legs raised, unless breathing is the main problem, in which case let them sit up. A second dose may be needed if there is no improvement in about five minutes. Every hazelnut-allergic child should have a written anaphylaxis action plan and two epinephrine auto-injectors that go everywhere the child goes.

This section is general. Your child’s own plan is the specific one, and it is the one to follow.

When you can’t tell what’s happening

The hardest moments are usually not the clear reactions. They are the ambiguous ones. A flushed cheek after a new food. A single cough. A child who says their tummy hurts an hour after a snack you did not pack. Telling the start of a reaction apart from an ordinary toddler complaint is genuinely hard, and it does not resolve cleanly from across the room. Hazelnut adds its own version: a child with the birch-linked, itchy-mouth pattern may have mild oral symptoms often enough that the one time it is something more does not announce itself.

The posture that works is to treat the spectrum, not to diagnose it in the moment. Know your action plan’s override signs cold, watch whether more than one body system is involved rather than fixating on a single symptom, and accept that you will sometimes give epinephrine or call the allergist for something that turns out to be nothing. That is the system working the way it is supposed to.

The competence here builds slowly, over many ambiguous afternoons. It shows up as a shorter pause before you act.

Treatment options

Strict avoidance is the floor, and everything else is decided on top of it. Avoidance plus a written action plan plus epinephrine within reach is the standing setup for hazelnut-allergic children. How wide the avoidance goes, whether it extends to walnut and pecan, and whether any form of hazelnut is ever worth a supervised challenge, is set by the component pattern from the components section, not by a blanket rule.

Hazelnut is like cashew, and unlike peanut, in one important way: there is no FDA-approved hazelnut treatment. There is no hazelnut version of Palforzia. What exists is experimental.

Hazelnut oral immunotherapy (experimental, not approved). Hazelnut OIT feeds measured, slowly increasing doses of hazelnut protein under medical supervision to train the body toward tolerance. It is offered in specialist and research settings, not as an approved product, and it is not standard of care (Giannetti 2023). In the Nut CRACKER controlled study, 29 of 30 treated patients (96.7 percent) reached full desensitization, against 2 of 14 controls, at a 1,200 mg hazelnut-protein maintenance dose (Elizur 2025). Two cautions come with that result. First, hazelnut OIT did not cross-protect against other tree nuts: it did not desensitize the cashew-co-allergic patients and was unlikely to help with walnut, so a child allergic to several tree nuts is not covered across nuts by hazelnut OIT alone (Elizur 2025). Second, build-up reactions are common: an Italian cohort reported reactions during OIT in about 82 percent of patients, with anaphylaxis in about 9 percent (Barni 2026). Enrollment thresholds, maintenance doses, and protocols vary by center, and because hazelnut OIT is investigational, this page does not name a starting dose. That is your allergist’s call, with you.

During active hazelnut OIT, the threshold for an incidental exposure is modulated. This matters only if your child is in or starting OIT. If you are not there yet, you can skip it for now.

Birch immunotherapy is sometimes raised, but is not a hazelnut treatment. Because the birch-linked form of hazelnut allergy comes through birch pollen, families sometimes ask whether birch-pollen allergy shots or drops would help. A 2024 systematic review found no significant change in the hazelnut reaction threshold and concluded there is not enough evidence that birch immunotherapy reduces birch-pollen-related food allergy (Kallen 2024). The page names this honestly: birch immunotherapy is not an established hazelnut treatment.

The broader pipeline. Multi-nut OIT protocols and adjunctive biologics such as omalizumab are under investigation, but none is a hazelnut-specific standard of care. The field moves; this is where it stands as of writing.

Not medical advice. Whether to treat at all, and how, is a conversation with your allergist.

Day-to-day living

School and day care. A hazelnut-allergic child needs a written plan on file, epinephrine truly accessible, trained staff, and a clear routine for snacks, classroom parties, and substitute teachers. In US public schools, a 504 plan is the usual way to put that in writing. Flag walnut and pecan alongside hazelnut if the component pattern points that way, and watch for chocolate-hazelnut spreads at parties.

Restaurants. The risk is cross-contact and hidden hazelnut more than the obvious menu item. Bakeries, dessert spots, gelaterias, and European or Middle Eastern restaurants carry higher hazelnut risk (chocolate spreads, praline, gianduja, baklava-adjacent pastries). A chef card that names hazelnut plainly does more than a verbal order across a loud kitchen.

Travel. Bring more epinephrine than you think you need, carry food you trust, and look up pharmacies and emergency numbers before you land. Hazelnut is especially common in European confectionery and on European children’s menus, so confirm crepes, pastries, and chocolate dishes carefully.

Holidays and gatherings. Chocolate assortments, gianduja and praline desserts, Nutella-filled treats, mixed-nut bowls, and baked goods made with nut flours are the hazelnut-dense settings. Bringing your child’s own food and being plain with hosts beats hoping a buffet is safe.

Prognosis and outgrowing

Hazelnut allergy, like tree-nut allergy generally, is usually not outgrown. The most-cited pediatric figure is about 9 percent resolution confirmed by a supervised food challenge (Fleischer 2005), and a hazelnut-focused review puts roughly 10 percent of young patients outgrowing tree-nut allergy, with most cases persisting into adulthood (Giannetti 2023). Resolution is more likely at lower whole-nut IgE levels (challenge-pass rates of about 58 percent at a tree-nut IgE at or below 5 kUA/L, and about 63 percent at or below 2 kUA/L), and a falling hazelnut IgE over time is associated with growing out of it (Fleischer 2005, Giannetti 2023).

Reassessment cadence is individualized, commonly every one to three years where the numbers are falling, more often for a younger child with a milder history and less aggressively after a severe, storage-protein-driven reaction. The one definitive test of outgrowing it is a supervised oral food challenge; falling numbers are encouraging but supportive, not proof.

Questions for your allergist

You do not have to walk in knowing the science. You have to walk in with the right questions, and these are them.

1. What are my child’s Cor a 14, Cor a 9, and Cor a 1 component results, not just whole-hazelnut IgE, and what does the pattern mean: the serious storage-protein kind or the milder birch-linked kind?
2. If the history is convincing but routine testing is negative, is oleosin (Cor a 12, 13, 15) testing available?
3. Should we treat walnut and pecan as off-limits too, and is a supervised challenge ever worth considering for them, or for almond, which is often over-avoided?
4. Which hidden hazelnut sources (chocolate spreads, gianduja and praline, coffee syrups, cosmetic oils) matter most for how we actually eat?
5. Is my child a candidate for hazelnut OIT given that it is experimental and not FDA-approved, and what are the trade-offs for us specifically?
6. If my child is in or considering hazelnut OIT, how does active treatment change the day-to-day vigilance around incidental exposure during build-up, and how do exercise, illness, or missed doses change it?
7. When and how should we reassess to see if the allergy is resolving?
8. What will epinephrine, and any treatment we are considering, actually cost us, and what does our insurance cover?

The frame: how to hold this

There are two worlds, and a severe food allergy moves a family from one into the other. In the recoverable world, a mistake is a lesson. A forgotten jacket is a cold afternoon. In the irrecoverable world, one wrong protein is not a lesson, because the cost of the error can be the child. When someone tells an allergy parent to relax, they are speaking from the first world to someone who has had to move to the second. They think the parent is anxious. The parent is not anxious. The parent is calibrated.

The work, then, is to sort what is on your side of the line from what is not. On your side: the labels you read, the Cor a 14 and Cor a 1 tests you ask for, the epinephrine that travels with the child, the chef card that names hazelnut, the plan on file at school. Not on your side: the kitchen that folds gianduja into a dessert and does not say so, the relative who thinks one chocolate is kindness, the manufacturer whose precautionary label is voluntary. You do the things on your side fully, and you stop apologizing for them. And you hold, without pretending otherwise, that the other side is real and partly random, and that a stacked defense reduces the risk without ever closing the gap to zero.

This page does not promise safety. It lays out the layers and names the gap, and it leaves the calibration to you and your allergist, who actually know your child.

Related pages on this site

• Hazelnut, walnut, and pecan cross-reactivity, the deep version
• Birch pollen and oral allergy syndrome: the PR-10 foods
• Where hazelnut hides: the full label-reading guide
• Hazelnut OIT, what “experimental” means
• Building a hazelnut 504 plan
• Restaurants and travel with a hazelnut-allergic child

These companion pages are being written and will be linked here as each one goes live.

Frequently asked questions

Is hazelnut a tree nut?

Yes. Hazelnut is a true tree nut in the Betulaceae (birch) family. That birch family link is why hazelnut allergy can be driven by birch pollen and why it has both a milder birch-linked form and a serious storage-protein form (see Components).

What is the difference between Cor a 14 and Cor a 1?

Cor a 14 is the serious marker: a storage protein tied to whole-body reactions, and it stays dangerous when the nut is roasted. Cor a 1 is the milder, birch-pollen-linked marker, more often tied to an itchy mouth. A component blood test tells them apart, which is why it is worth asking for by name (see Components).

Can my hazelnut-allergic child eat other tree nuts?

It depends on the nut and is a tested question, not an assumption. Walnut and pecan often travel with hazelnut, so treat them as off the list until an allergist clears them. Almond is the opposite case, the least cross-reactive tree nut, so do not drop almond on a hazelnut allergy alone; test it (see Cross-reactivity).

Does roasting or cooking make hazelnut safe?

Not for the serious kind. The storage proteins (Cor a 9 and Cor a 14) are heat-stable and survive cooking, so roasted or baked hazelnut stays dangerous for a storage-protein-sensitized child (Pfeifer 2015). Whether any form of hazelnut is safe for a given child is your allergist’s call, not something to test at home.

Is there a treatment for hazelnut allergy?

There is no FDA-approved hazelnut treatment. Hazelnut oral immunotherapy is experimental and offered only in specialist settings; in one controlled study it desensitized most treated children but did not protect against other tree nuts (Elizur 2025). It is a conversation with your allergist, not a self-directed step (see Treatment options).

References and medical review

This page is pending independent medical review; the note at the top of the page applies until a reviewer is assigned. The references below resolve every in-body citation. The cross-reactivity, component, and hidden-source claims (the storage-protein red flag, the walnut and pecan overlap, the relaxed almond guidance, the European confectionery and cosmetic-oil sources, and the coconut reassurance) are drawn from the project’s verified cross-reactivity and hidden-source floor, each carrying its own source there.

1. Datema MR, Zuidmeer-Jongejan L, Asero R, et al. Hazelnut allergy across Europe dissected molecularly: A EuroPrevall outpatient clinic survey. J Allergy Clin Immunol. 2015;136(2):382-391. https://doi.org/10.1016/j.jaci.2014.12.1949
2. Caffarelli C, Mastrorilli C, Santoro A, et al. Component-Resolved Diagnosis of Hazelnut Allergy in Children. Nutrients. 2021;13(2):640. https://doi.org/10.3390/nu13020640
3. Pfeifer S, Bublin M, Dubiela P, et al. Cor a 14, the allergenic 2S albumin from hazelnut, is highly thermostable and resistant to gastrointestinal digestion. Mol Nutr Food Res. 2015;59(10):2077-2086. https://doi.org/10.1002/mnfr.201500071
4. Elizur A, Appel MY, Goldberg MR, et al. Hazelnut Oral Immunotherapy Desensitizes Hazelnut But Not Other Tree Nut Allergies (Nut CRACKER Study). J Allergy Clin Immunol Pract. 2025;13(4):833-841.e4. https://doi.org/10.1016/j.jaip.2024.12.041
5. Barni S, et al. Hazelnut oral immunotherapy in children: an Italian single-center retrospective cohort study. Pediatr Allergy Immunol. 2026. https://doi.org/10.1111/pai.70287
6. Fleischer DM, Conover-Walker MK, Matsui EC, Wood RA. The natural history of tree nut allergy. J Allergy Clin Immunol. 2005;116(5):1087-1093. https://doi.org/10.1016/j.jaci.2005.09.002
7. Giannetti A, Ruggi A, Ricci G, Gianni G, Caffarelli C. Natural History of Hazelnut Allergy and Current Approach to Its Diagnosis and Treatment. Children (Basel). 2023;10(3):585. https://doi.org/10.3390/children10030585
8. Lyons SA, Clausen M, Knulst AC, et al. Prevalence of Food Sensitization and Food Allergy in Children Across Europe. J Allergy Clin Immunol Pract. 2020;8(8):2736-2746.e9. https://doi.org/10.1016/j.jaip.2020.04.020
9. Kallen A, et al. The effect of subcutaneous and sublingual birch pollen immunotherapy on birch pollen-related food allergy: a systematic review. Front Allergy. 2024;5:1360073. https://doi.org/10.3389/falgy.2024.1360073
10. Food Allergen Labeling and Consumer Protection Act of 2004 (FALCPA), Title II of PL 108-282. https://www.fda.gov/food/food-allergensgluten-free-guidance-documents-regulatory-information/food-allergen-labeling-and-consumer-protection-act-2004-falcpa
11. Regulation (EU) No 1169/2011 (Annex II allergens, nuts). https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX%3A32011R1169