What Are Tree Nut Allergies?

Tree nut allergy is one of the most common food allergies in both children and adults and it’s also one of the eight most allergenic foods known to cause severe allergy attacks. Nearly all tree nuts have been associated with fatal allergic reactions. Even the smallest amount of tree nuts can cause an allergic reaction, so it’s important to know how to avoid exposure to products containing tree nuts and be able to spot the symptoms of an allergic reaction if one is ingested.

A tree nut allergy is a type of immune response triggered by ingesting one of the tree nuts, which include walnut, almond, hazelnut, cashew, pistachio, pecans, macadamia nuts, and Brazil nuts. The immune system normally reacts to allergens by protecting us from any kind of a negative response. However, the immune response of an individual with a food allergy is oversensitive. When faced with an allergen, the system reacts by releasing substances that cause allergy symptoms.

While tree nut allergies tend to be lifelong, about 9% of individuals who are allergic to tree nuts as children later grow out of the allergy.

Link to Peanut Allergies

Not everyone who is allergic to tree nuts will also be allergic to peanuts (and vice versa). However, studies have shown that between 25% and 40% of people who have a peanut allergy will also be allergic to one or more tree nuts.

People with tree nut allergies who are not allergic to peanuts should still avoid peanut products, as the potential for cross-contamination is very high. Food manufacturers often use a variety of nuts in their processing facilities, and tree nuts and peanuts can easily get mixed together or used in the same machines.

Tree Nuts That Can Cause Allergic Response

  • Almonds*
  • Artificial nuts
  • Beechnut
  • Brazil nut*
  • Butternut
  • Cashew*
  • Chestnut
  • Chinquapin nut
  • Filbert/hazelnut*
  • Ginkgo nut
  • Hickory nut
  • Litchi/lichee/lychee nuts
  • Macadamia nut*
  • Nangai nut
  • Pecan*
  • Pesto
  • Pili nut
  • Pine nut*
  • Pistachio*
  • Praline
  • Shea nut
  • Walnut*

* Most commonly consumed tree nuts.

Avoiding Exposure to Tree Nut Products

Even trace amounts of a food allergen can cause a reaction. So, in order to prevent an allergic reaction to tree nuts, you must avoid tree nuts in all forms. Some common products that contain various types of tree nuts include:

  • Black walnut hull extract (flavoring)
  • Gianduja (a chocolate-nut mixture)
  • Natural nut extract/distillates/alcoholic extracts
  • Nut butters and nut oils

Additionally, tree nut proteins can be found in the following:

  • Cereals, crackers, cookies, candy, chocolates, energy bars
  • Flavored coffee, frozen deserts, marinades, bbq sauces, and some cold cuts
  • Personal hygiene products such as lotions, shampoos, perfumes, and soaps
  • Ice cream parlors, bakeries, and certain restaurants (Chinese, African, Thai, and Vietnamese) are considered high risk for people with tree nut allergy

Tree Nut Allergy Symptoms

The most common cause of tree nut allergy is direct contact by eating one of the tree nuts or tree-nut containing foods. People with a tree nut allergy may experience an allergic reaction anywhere from a few minutes to a few hours after consuming the allergen.

Most Common Symptoms of Tree Nut Allergies

  • Abdominal pain, cramps, nausea, and vomiting
  • Diarrhea
  • Itching of the mouth, throat, eyes, skin or other area
  • Difficulty swallowing
  • Shortness of breath
  • Wheezing
  • Nasal congestion or runny nose

In severe cases, tree nut allergies can also result in anaphylaxis, a sudden, severe, and life-threatening allergic reaction that can involve several areas of the body. If you have a tree nut allergy, it is recommended to keep an epinephrine auto-injector with you at all times. An epinephrine injection is the only treatment for anaphylaxis.

Special Considerations for Tree Nut Allergies

If you have an allergic reaction to one of the tree nuts, your doctor may recommend that you stay away from all tree nuts because you have a higher chance of being allergic to other types of nuts. However, some people who are allergic to one particular nut still safely eat other tree nuts. A careful conversation with your doctor and allergist is recommended before you sample other tree nuts.

The other issue facing people with a tree nut allergy is cross-contact. Cross-contact can happen when a food is exposed to tree nuts during processing or handling. For example, a kitchen tool (i.e., a spoon) that was previously used to stir a mixture with almond butter is now being used to serve a “non-tree nut” meal. Even though the meal does not contain tree nut products, the spoon (with almond butter on it) has now introduced the allergen into the food.

There are several steps involved in testing for and diagnosing a tree nut allergy. Consult your allergist or physician for further information. You may also want to discuss being tested for an allergy to peanuts, since people who are allergic to tree nuts may also have an allergic reaction to peanuts.

Regulations Related to Tree Nut Allergies

The U.S. Food and Drug Administration (FDA) is primarily responsible for enforcing the Food Allergen Labeling and Consumer Protection Act of 2004 (FALCPA), which requires that food labels clearly identify the food source names of any ingredients that are one of the major food allergens – including tree nuts – or contain any protein derived from a major food allergen.

The law further explains that the name of the food source of a major food allergen must appear in parentheses following the name of the ingredient or next to the list of ingredients in a “contains” statement.

Unfortunately, the FALCPA’s labeling requirement does not apply to products that may be contaminated due to cross-contact. The FDA does not regulate statements such as: “may contain tree nuts,” or “manufactured on shared equipment with tree nuts” or “manufactured in the same facility as tree nuts” so there is no guarantee that products labeled as such are safe.

Please be advised that some alcoholic beverages may contain nuts or nut flavoring added in the distillation process and most of these are not covered by the FALCPA’s labeling requirements. Contact the manufacture for further clarification.