What Is Tree Nut Allergy?
Tree nut allergies are among the most common food allergies in both children and adults. The six tree nut allergies most common in children and adults are to walnut, almond, hazelnut, pecan, cashew, and pistachio.
Approximately 50% of children who are allergic to one tree nut are allergic to another. ¹ And approximately two-thirds of patients allergic to cashew or walnut are also allergic to pistachio or pecan, respectively. Most children who are allergic to one or more tree nuts do not outgrow their tree nut allergy.
When a person with an allergy to a particular tree nut is exposed to that tree nut, proteins in the nut bind to specific IgE antibodies made by the person’s immune system. This binding triggers the person’s immune defenses, leading to reaction symptoms that can be mild or very severe.
In the U.S., plain-language labeling on packaged foods is required for 12 different tree nuts. Tree nuts are different from peanuts, which grow underground and are part of the legume (bean and pea) family. Tree nuts are also different from seed allergens, such as sesame, sunflower, poppy, and mustard.
Research shows that over 2% of the pediatric population is affected by allergies to tree nuts, and many will carry these allergies into adulthood. ²
Allergic Reactions to Tree Nuts
Tree nuts can cause a severe and potentially life-threatening allergic reaction (anaphylaxis). Allergic reactions can be unpredictable, and even very small amounts of tree nuts can cause a serious allergic reaction.
If you have a tree nut allergy, keep an epinephrine delivery device with you. Epinephrine is the first-line treatment for anaphylaxis.
Avoiding Tree Nuts
To prevent a reaction, you must avoid all tree nuts and tree nut products.
If you are 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 tree nuts. You may also be advised to avoid peanuts because of the higher likelihood of cross-contact during manufacturing and processing.
Tree nuts, as a food category, are one of the nine major food 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: Tree nuts [type]” statement on the package. This makes it easy to see if tree nuts are present in a food item.
Note that in 2025, FDA guidance on food allergen labeling was updated, with important changes for tree nuts specifically. Read more about the change. The 12 tree nut species specifically designated by the FDA guidance as requiring food allergen labeling are included in boldface in the list below.
Avoid foods that contain tree nuts or any of these ingredients:
- Almond
- Artificial nuts
- Beechnut
- Black walnut, including hull extract (flavoring)
- Brazil nut
- Butternut (also known as white walnuts; not squash)
- California walnut
- Cashew
- Chestnut
- Chinquapin nut
- Coconut*
- Filbert/hazelnut
- Gianduja (a chocolate-hazelnut spread or mixture)
- Ginkgo nut
- Heart nut (also known as Japanese walnut)
- Hickory nut
- Litchi/lichee/lychee nut
- Macadamia nut (also known as bush 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 (often includes pine puts or walnuts)
- Pili nut
- Pine nut (also referred to as Indian, pignoli, pigñolia, pignon, piñon and pinyon nut)
- Pistachio
- Praline
- Shea nut
- Walnut (English or Persian)
- Walnut hull extract (flavoring)
Some Unexpected Sources of Tree Nuts
Allergens are not always present in these foods and products, but you cannot 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, confections, 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 a high risk of cross-contact.
Tree nut oils such as walnut and almond, which often are not highly refined, are sometimes used in lotions, hair care products, and soaps.
Crushed walnut shells may be used in “natural” sponges or brushes due to durability.
Some alcoholic beverages may contain nut flavoring, so consider avoiding these too. Because alcoholic beverages are not federally regulated in terms of food allergen labeling, you may need to call the manufacturer to determine the safety of ingredients, such as natural flavoring.
There are no documented cases of food allergic 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 food allergy reactions. While it is not a common food in the U.S., you will often find it in Morocco. Argan oil is also used in many personal care and cosmetic products available in the U.S.
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 vegetables with “pepper” in their name (e.g., bell peppers, red peppers, or chili peppers).
*Coconut, the seed of a drupaceous fruit, has typically not been restricted in the diets of people with a tree nut allergy. However, for a period spanning October 2006 to December 2024, the U.S. Food and Drug Administration identified coconut as a tree nut requiring food allergen labeling.
Will My Child Outgrow a Tree Nut Allergy?
An allergy to tree nuts tends to be lifelong. Research shows that about 9 percent of children with a tree nut allergy eventually outgrow their allergy.1
Tree Nut Allergy Allergy Resources
1McWilliam V, et al. Patterns of tree nut sensitization and allergy in the first 60 years of life in a population-based cohort. J Allergy Clin Immunol 2019;143(2):644.
2McWilliam V, et al. The prevalence of tree nut allergy: a systemic review. Curr Allergy Asthma Rep 2015;15(9):54.
3Warren, C. M., Sehgal, S., Nimmagadda, S. R., & Gupta, R. (2023). Prevalence and burden of coconut allergy in the United States. Annals of Allergy Asthma & Immunology, 131(5), 645-654.e2. https://doi.org/10.1016/j.anai.2023.08.017
