How to identify a tree nut allergy

Tree Nut | Causes, Symptoms & Treatment


An allergy to tree nuts is one of the most common food allergies. Along with peanuts and shellfish, it is also one of the food allergens most frequently linked to anaphylaxis, a potentially life-threatening reaction that impairs breathing and can send the body into shock.

Symptoms of a tree nut allergy include:

  • Abdominal pain, cramps, nausea and vomiting
  • Diarrhea
  • Difficulty swallowing
  • Itching of the mouth, throat, eyes, skin or any other area
  • Nasal congestion or a runny nose
  • Nausea
  • Shortness of breath
  • Anaphylaxis (less common)

If you experience any of these symptoms after consuming tree nuts, see an allergist.


Because a tree nut allergy can cause a life-threatening reaction, an accurate diagnosis is essential. Your allergist will start by taking a medical history, asking about any previous allergic reactions and about any family history of allergies. Skin-prick tests and/or blood tests may be used to determine the presence of allergen-specific immunoglobulin E, an antibody that binds to allergens and triggers the release of chemicals that cause symptoms.

If those tests are inconclusive, your allergist may order an oral food challenge. In this test, a patient is fed tiny amounts of the suspected allergy-causing food in increasing doses over a period of time, under strict supervision in an allergist’s office or a food challenge center. Emergency medication and emergency equipment must be on hand during this procedure.

Management and Treatment

As with most food allergies, the best way to avoid triggering an allergic reaction is to avoid eating the offending item.

People who are diagnosed with an allergy to a specific tree nut may be able to tolerate other tree nuts, but allergists usually advise these patients to avoid all nuts. Tree nuts are often used as garnishes in salads, as an ingredient in Asian dishes, and as an ice cream topping. They may also be found in baking mixes, breading, sauces, desserts and baked goods.

Tree nuts are among the eight most common food allergens affecting adults and children, and are specifically mentioned in the Food Allergen Labeling and Consumer Protection Act (FALCPA) of 2004. This means that the presence of these items must be highlighted, in clear language, on ingredient lists. Some companies may voluntarily include information that their food products that don’t contain nuts were manufactured in a facility that also processes nuts, though such a statement is not required by law. It is important for people with tree nut allergies to read labels carefully.

Some alcoholic beverages may contain nuts or nut flavoring added in the distillation process.  Most alcoholic beverages aren’t covered by the FALCPA requirements; if “natural flavors” or “botanicals” are cited as an ingredient, you may need to call the manufacturer to determine whether that indicates the presence of nuts or nut flavoring.

Tree nut oils, which may contain nut protein, can be found in lotions, hair care products and soaps; those allergic to tree nuts should avoid using these products. Fortunately, allergists are specially trained to help identify these hidden sources of tree nut allergens.

Tree nuts and peanuts

There’s often confusion between peanuts and tree nuts. Peanuts are legumes, not nuts; still, between 25 and 40 percent of individuals who are allergic to peanuts also react to at least one tree nut, according to studies.

Allergists generally advise people who are allergic to tree nuts also to avoid peanuts because of the risk of cross-contact and cross-contamination between tree nuts and peanuts in food processing facilities. If you or your child is allergic to either peanuts or tree nuts, ask your allergist whether you should avoid both products.

The prevalence of these allergies in children appears to be growing, according to a 2010 study that compared data from telephone surveys of 5,300 U.S. households in 1997, 2002 and 2008. In the 2008 survey, 2.1 percent of respondents reported having a child with an allergy to peanuts, tree nuts or both. In the 2002 survey, 1.2 percent of subjects said they had a child with one or both of these allergies; five years earlier, in 1997, only 0.6 percent of respondents reported having a child with one or both of these allergies.

Allergies to tree nuts and peanuts are among the most common causes of anaphylaxis in the United States. An allergist will advise patients with these allergies to carry an auto-injector containing epinephrine (adrenaline), which is the only treatment for anaphylactic shock, and will teach the patient how to use it. If a child has the allergy, teachers and caregivers should be made aware of his or her condition as well.

People with tree nut allergies often wonder if they must also avoid coconut and nutmeg.

Coconut is not a botanical nut; it is classified as a fruit, even though the Food and Drug Administration recognizes coconut as a tree nut. While allergic reactions to coconut have been documented, most people who are allergic to tree nuts can safely eat coconut. If you are allergic to tree nuts, talk to your allergist before adding coconut to your diet.

Nutmeg is a spice that is derived from seeds, not nuts. It may be safely consumed by people with a tree nut allergy.

Use the Find an Allergist tool to find expert care for your tree nut allergy.

Tree Nut -

To prevent a reaction, it is very important that you avoid all tree nuts and tree nut products.

If you’re allergic to one type of tree nut, you have a higher chance of being allergic to other types. For this reason, your doctor may recommend you avoid all nuts. You may also be advised to avoid peanuts because of the higher likelihood of cross-contact with tree nuts during manufacturing and processing. These issues should be discussed and further evaluated by your allergist and specific allergy testing may be warranted. 

Tree nuts are one of the eight major allergens that must be listed in plain language on packaged foods sold in the U.S., as required by federal law, either within the ingredient list or in a separate “Contains” statement on the package. For tree nuts, the specific variety must also be identified on the package. This makes it easy to see if tree nuts are present in a food item. 

Avoid foods that contain tree nuts or any of these ingredients:

  • Almond
  • Artificial nuts
  • Beechnut
  • Black walnut hull extract (flavoring)
  • Brazil nut
  • Butternut
  • Cashew
  • Chestnut
  • Chinquapin nut
  • Coconut
  • Filbert/hazelnut
  • Gianduja (a chocolate-nut mixture)
  • Ginkgo nut
  • Hickory nut
  • Litchi/lichee/lychee nut
  • Macadamia nut
  • Marzipan/almond paste
  • Nangai nut
  • Natural nut extract (e. g., almond, walnut—although artificial extracts are generally safe)
  • Nut butters (e.g., cashew butter)
  • Nut distillates/alcoholic extracts
  • Nut meal
  • Nut meat
  • Nut milk (e.g., almond milk, cashew milk)
  • Nut oils (e.g., walnut oil, almond oil)
  • Nut paste (e.g., almond paste)
  • Nut pieces
  • Pecan
  • Pesto
  • Pili nut
  • Pine nut (also referred to as Indian, pignoli, pigñolia, pignon, piñon and pinyon nut)
  • Pistachio
  • Praline
  • Shea nut
  • Walnut
  • Walnut hull extract (flavoring)

Some Unexpected Sources of Tree Nuts

Allergens are not always present in these food and products, but you can’t be too careful. Remember to read food labels and ask questions about ingredients before eating a food that you have not prepared yourself.

Tree nut proteins can be found in some surprising places, such as cereals, crackers, cookies, candy, chocolates, energy bars, flavored coffee, frozen desserts, marinades, barbeque sauces and some cold cuts, such as mortadella.

Ice cream parlors, bakeries, coffee shops and certain restaurants (e.g., Chinese, African, Indian, Thai and Vietnamese) are considered high risk for people with tree nut allergy. Even if you order a tree nut-free dish, there is high risk of cross-contact.

Tree nut oils, such as walnut and almond, are sometimes used in lotions, hair care products and soaps.

Crushed walnut shells may be used in “natural” sponges or brushes due to their durability. 

Some alcoholic beverages may contain nut flavoring, so consider avoiding these as well. Because these beverages are not federally regulated, you may need to call the manufacturer to determine the safety of ingredients such as natural flavoring.

Coconut, the seed of a drupaceous fruit, has typically not been restricted in the diets of people with a tree nut allergy. However, in October 2006, the U.S. Food and Drug Administration began identifying coconut as a tree nut. Medical literature documents a small number of allergic reactions to coconut; most occurred in people who were not allergic to tree nuts.

There is only one documented case of someone reacting to coconut oil, and there are no documented cases of reactions to shea nut oil or butter. Therefore, it would be extremely rare for someone to react to one of these.

Argan oil is derived from the nut of the argan tree and has rarely been reported to cause allergic reactions. While it is not a common food in the U.S., you will often find it in Morocco.

People with cashew allergy may be at higher risk for allergy to pink peppercorn (known as Brazilian Pepper, Rose Pepper, Christmasberry and others). This dried berry (Schinus, related to cashew) is used as a spice but is different from standard black pepper and fruits with “pepper” in their name (e.g., bell peppers, red peppers or chili peppers).

It is useful to know 90,000 about nuts, almonds and arahis (nètter / mandler / peanuffa)

nuts, almonds and peanuts ( N tter Mandler Ø PEAN 000 000 000 PEAN 000 000 PEAN 000 PEANs tter )

Useful information about nuts, almonds and peanuts - Norwegian Asthma and Allergy Association Information Sheet

What is a nut allergy?

By nuts we mean hazelnuts, cashews, pistachios, walnuts, pecans, almonds, American nuts and macadamia nuts. From a biological point of view, the peanut, or peanut, is not a nut, but belongs to the leguminous family. Therefore, some people who are allergic to peanuts also show sensitivity or allergic symptoms when they eat leguminous plants: green peas, soybeans, beans, lupins, and lentils. Coconut, nutmeg and water chestnut are also in a different family and do not cross-react with nuts/peanuts. Although there is a possibility of having an allergy to coconut, this is quite rare.

An allergic reaction to food occurs when the body reacts to certain types of proteins found in food. Nut allergy is considered one of the most common food allergies and is one of those that often accompany you throughout your life. One reason for the prevalence of this allergy is the fact that a large proportion of the population suffers from pollen allergies leading to cross-allergies and/or reactions, in particular to nuts.

What is the allergic reaction to nuts, almonds and peanuts?

Allergies to tree nuts, almonds and peanuts can lead to a very severe reaction, but not for everyone with this disease. Common reactions of the body to the intake of nuts are itching and swelling of the mouth and throat. An attack of eczema, hives, abdominal pain and nausea are possible symptoms. In some cases, life-threatening reactions (anaphylactic shock) may occur. A reaction to eating almonds is not as common as a reaction to nuts.

Observations show that children have a stronger reaction than adults. Approximately half of children who are allergic to peanuts react to smell, taste, or touch, while less than 10% of adults react in this way.

What does the body react to?

The reaction is caused by proteins found in nuts, almonds and peanuts. For some, a severe allergic reaction can be caused by both the ingestion of nuts and the nut dust in the room. Common reactions to nut dust are allergic rhinitis, worsening eczema, and asthma attacks.

How to deal with allergies to tree nuts, almonds and peanuts?

Protection against food allergies is the elimination of intolerable foods from the diet. In the case of a nut allergy, this means that the nut or nuts to which the person is allergic must be eliminated from the diet. Some people are allergic to all types of nuts, and some believe that the easiest way is to eliminate all types of nuts from the diet. This issue should be discussed separately in each case with the attending physician. Nuts and peanuts have few allergens in common. This means that the likelihood that a person with a nut allergy will also react to peanuts or other nuts is small, except for those types of nuts that are closely related to the allergy-causing ones.

Where can nuts, almonds and peanuts be found?

Nut-based foods include nougat, nut cream, sugar-roasted almonds, biscuit fillers, holiday biscuits, and almond cake base. Other foods often containing nuts include cakes, cookies, breakfast mixes, salads, breads, desserts, chocolate, ice cream, pesto, and some foreign cuisines such as Asian.

Some vegetable oils may be made from nuts. In refined products, proteins, as a rule, do not remain. Conversely, cold-pressed oils may contain protein residues.

Food Labeling:

All nuts and peanuts must be clearly marked on the label, with the name of the nut listed as an ingredient, when included in a recipe. The labeling obligation also applies to unpackaged food, such as those sold unpackaged in shops, restaurants, canteens and other places.

Some foodstuffs are labeled "may contain traces of nuts". This does not mean that nuts have been added to the product. Nut residues may have been introduced into the product during the manufacturing process. These small amounts of nuts are tolerated by most allergy sufferers who can eat these labeled foods. However, depending on the severity of the allergy, some people should consult a doctor about foods containing traces of nuts.

Allergen f256 - walnut, IgE (ImmunoCAP)

Walnut as an etiological factor of food allergy is classified as a high degree of allergenic activity (without taking into account individual characteristics). It is a common "hidden" allergen - it is often used in the manufacture of confectionery, pastries, sauces. Cross-allergy to tree pollen (birch, alder, hazel) is often observed. An allergic reaction to nuts, including walnuts, can often occur in the form of a severe attack of bronchial asthma.

Synonyms Russian

Specific immunoglobulins class E (IgE) to walnut.

Synonyms English

Allergen f256 - Walnut, IgE.

Test method

Solid phase immunofluorescence (ImmunoCAP).


kU/l (kilo unit of allergen per litre).

What biomaterial can be used for research?

Venous blood.

How to properly prepare for an examination?

  • Do not smoke for 30 minutes before the test.

General information about the study

Walnuts are widely consumed in their natural form, as part of confectionery and many other dishes. Walnut oil is used in cooking, and is also added to varnishes for painting, soaps, and cosmetics. The walnut tree belongs to valuable species, harvested in small quantities and used for the manufacture of high-quality furniture.

The most common allergic reaction after eating nuts, which can be severe (respiratory allergy to walnut pollen is also possible).

According to statistics, 90% of all deaths caused by food allergy attacks are nut allergies. Of all the other types of food allergies, it is the most persistent - if it manifests itself in several varieties of nuts at once. There is a good chance that a single nut allergy will go away on its own over time. If there is an allergy to several types of nuts at once (peanuts, walnuts, hazelnuts, cashews and others), there is no such probability at all. The composition of walnuts includes fatty oil, proteins, carbohydrates, provitamin A, vitamins K and P, amino acids (asparagine, cystine, glutamine, serine, histidine, valine, phenylalanine). Fatty oil consists of glycerides of linoleic, oleic, stearic, palmitic and linolenic acids. All listed substances can have a strong sensitizing activity. Moreover, with thermal exposure (frying, cooking), it can increase.

Many foods contain traces of nuts: chocolate, ice cream, candies, baked goods, yogurts, quick breakfasts, etc. , olives, cherries, corn, grapes, in contact with birch and alder pollen.

Allergy symptoms may appear as early as 3-5 minutes after contact with the allergen, usually increase over time and reach a maximum after 1-3 hours. Allergic symptoms include local (burning, itching, tingling sensation and swelling of the tongue, lips , palate and gums, perspiration, rashes near the mouth, peeling of the zone of the labial red border, the so-called oral allergic syndrome) and general manifestations. Allergy is accompanied by urticaria with characteristic redness, burning and itching. Rashes can be of a different nature, they are most susceptible to the face, abdomen, chest. There may also be a runny nose, sore throat, swelling, shortness of breath, sneezing, coughing, watery eyes, swelling of the lips. An allergic person with a food allergy often develops gastrointestinal disorders. Difficult cases may be accompanied by asthma attacks, Quincke's edema or anaphylactic shock.

The purpose of this study is to determine specific IgE to the walnut allergen using ImmunoCAP. Allergy diagnostics with ImmunoCAP technology is characterized by high accuracy and specificity, which is achieved by detecting even low concentrations of IgE antibodies in a very small amount of the patient's blood. The study is based on the immunofluorescence method, which allows to increase the sensitivity by several times compared to other diagnostic methods. Worldwide, up to 80% of the determinations of specific IgE immunoglobulins are performed by this method. WHO and the World Allergy Organization recognize ImmunoCAP diagnostics as the "gold standard", as this technique has proven its accuracy and stability of results in independent studies.

What is research used for?

  • Detection of sensitization to walnuts in children and adults;
  • determination of possible causes of an exacerbation of an allergic disease (allergic rhinitis / rhinoconjunctivitis, bronchial asthma, atopic dermatitis, urticaria, anaphylactic shock, angioedema, disruption of the gastrointestinal tract).

When is the test scheduled?

  • For suspected walnut allergy in patients;
  • when examining patients with polysensitization;
  • when examining patients with clinical manifestations of allergic reactions (skin rashes, angioedema, redness and burning in the oral cavity, swelling of the eyelids, lacrimation, sneezing, congestion, rhinorrhea, cough, shortness of breath, bronchospasm, nausea, vomiting, diarrhea) after eating walnuts;
  • if skin testing is not possible.

What do the results mean?

Reference values: 0. 00 - 0.35 kU/L.

Reasons for the increased result:

  • walnut sensitization.

Reasons for negative result:

  • no sensitization to this allergen;
  • prolonged restriction or exclusion of exposure to the allergen.

Important Notes

  • Performing this study is safe for the patient compared to skin tests (in vivo), as it eliminates the patient's exposure to the allergen. Taking antihistamines and age characteristics do not affect the quality and accuracy of the study.

Also recommended

  • Serum total immunoglobulins E (IgE)
  • Fadiatop (ImmunoCAP)
  • Fadiatop Child (ImmunoCAP)
  • Allergen f309 - chickpeas (chickpeas), IgE
  • Allergen f202 - cashew nut, IgE
  • Allergen f203 - pistachio nuts, IgE

+ determination of class E specific immunoglobulins to other allergens

Who orders the examination?

Allergist, gastroenterologist, dermatologist, pediatrician, internist, general practitioner.

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