Tree Nut Allergy: Symptoms, Testing, and Treatment

Tree nut allergy is one of the most common allergies found in children and adults. Once diagnosed, a tree nut allergy can be lifelong. Only 9 percent of children will naturally outgrow their tree nut allergy by the time they are adults. 

Often confused with a peanut allergy (peanuts are actually legumes), a tree nut allergy is triggered by proteins found in nuts such as walnuts, almonds, hazelnuts, pecans, cashews, Brazil nuts, pistachios, macadamia nuts, and pine nuts. Between 25–40 percent of those with a peanut allergy are also allergic to at least one type of tree nut. And similar to a peanut allergy, during an allergic reaction to a tree nut, food proteins bind to IgE antibodies, triggering an immune system response that results in a wide range of mild to severe reactions.

Symptoms of a Tree Nut Allergy Reaction

An allergic reaction to tree nuts may last anywhere from a matter of minutes to hours. Common mild symptoms of a tree nut allergy reaction include:

    • Nasal congestion or a runny nose
    • Swelling or itching in the mouth or throat
    • Constriction of the throat
    • Itching of the eyes or skin
    • Shortness of breath
    • Difficulty breathing / wheezing
    • Nausea and vomiting
    • Abdominal pain or cramps
    • Diarrhea
    • Difficulty swallowing
    • Anxiety
    • Headache
    • Hives

Severe reactions can result in anaphylaxis, which can cause the body to go into shock. Signs of a severe anaphylactic reaction include:

    • Pale or bluish tint to the skin
    • Drop in blood pressure
    • Swelling of the throat and/or tongue
    • Weak or rapid pulse
    • Constriction of the throat
    • Confusion and/or dizziness
    • Fainting or loss of consciousness

Anaphylaxis is a medical emergency — call 911 and/or seek medical care, and treat immediately with epinephrine. Children and adults with a tree nut allergy should always carry two epinephrine auto-injectors to ensure rapid treatment in case of accidental ingestion or contact.


Tree Nut Allergy Testing and Diagnosis

There are four ways to determine whether someone has a tree nut allergy. These include: 

Skin Prick Test

This is a safe and low-risk test in which the skin is lightly pricked with an allergen. Any skin reactions are closely observed and monitored by a clinician. Most reactions appear as bumps or hives, with mild itchiness as the most common side effect.

Blood Test

A blood test will measure the amounts of specific IgE antibodies that the immune system has deployed as a response to nut proteins. Once drawn, the blood is sent to a lab to be evaluated. Blood tests are safe for infants and children, as well as adults. While the results of a skin prick test are immediate, the results from a blood test often take a few days.

Component Test

A component test is a form of a blood test that assesses whether a patient can tolerate certain components of nut protein. This test provides heightened clarity to a clinician and helps determine if there is a higher risk of anaphylaxis to that food, while identifying if there are specific aspects that may be less harmful. Component testing is available and reliable for walnuts, cashews, hazelnuts, and Brazil nuts

Oral Food Challenge

This test is particularly useful as the final step in determining whether a food allergy has been outgrown, or when skin and blood tests are inconclusive. An oral food challenge can determine, with certainty, whether tree nuts may safely be consumed. This step is only taken after a full review of patient history and only in cases where a clinician determines that a patient is likely to successfully and safely pass the food challenge. Under close supervision and observation, the patient will consume very small amounts of a specific tree nut in increasing amounts over a three- to four-hour time period.

Ingredients to Avoid for Tree Nut Allergy

Each tree nut allergy is unique and may encompass one or multiple types of tree nuts. Common ingredients to avoid for tree nut allergy include:

    • Walnuts
    • Pistachios
    • Almonds
    • Brazil nuts
    • Hazelnuts
    • Cashews
    • Pecans
    • Beechnuts
    • Butternuts
    • Macadamia nuts
    • Hickory nuts
    • Nut meal
    • Pralines
    • Walnut hull extract
    • Pine nuts

Most who suffer from tree nut allergy experience adverse effects from walnuts, pecans, cashews, Brazil nuts, or pistachios. While diagnosed almond allergy may be uncommon, and hazelnut is also less common, both nuts can often trigger a reaction or Oral Allergy Syndrome that is related to cross-reactions to pollen. And while the FDA considers coconut as part of the tree nut family, it is actually a fruit and does not fall under the tree nut family of allergens. A diagnosed coconut allergy is generally uncommon.

Foods That Commonly Contain Tree Nuts

The FDA requires that tree nuts be clearly labeled on packaging, as tree nuts represent one of the most common and severe food allergies. Tree nuts can be found in a wide variety of foods, ranging from sauces and condiments to baked goods and beverages. Examples of foods that commonly contain tree nuts include:

    • Cereal
    • Granola and granola bars
    • Energy bars
    • Crackers
    • Cookies
    • Pesto
    • Nut flours
    • Flavored coffee
    • Almond milk
    • Pecan pie
    • Macarons
    • Nutella
    • Ice cream
    • Candy bars
    • Marinades
    • Barbeque sauces
    • Fudge
    • Marzipan
    • Nut liqueurs

While some foods may be more obvious than others (such as nut-based flour or milk), tree nuts can often be hidden in unlikely places. Those with a tree nut allergy should ensure that all labels and packaging are free from their specific allergens to avoid accidental exposure.

Tree Nut Allergy Treatment Options

Oral immunotherapy (OIT) can be used to treat tree nut allergy in patients of all ages. OIT is a safe and effective treatment to minimize reactions to contact with food allergens, protecting against accidental exposure and empowering patients to eat a balanced, full diet with confidence. 

OIT gradually exposes the patient to small doses of allergens over time. This desensitizes the body and helps to retrain the immune system, decreasing adverse allergic reactions. At Latitude Food Allergy Care, oral immunotherapy is offered with or without Xolair: an anti-IgE monoclonal antibody that helps suppress allergic reactions for some patients.

In some cases, the treatment of one nut allergy may also protect from another. For example, OIT treatment for cashew allergy can also protect against adverse reactions to pistachio. Similarly, OIT treatment for walnut allergy can protect against allergic reactions to pecans. Emerging research suggests that walnut allergy treatment may even cross-protect hazelnut, too.

For many people, oral immunotherapy also provides dramatic improvements in overall quality of life. Studies have shown that OIT is approximately 85% effective when performed by a skilled clinician who specializes in food allergy treatment. At Latitude, we are proud that 92% of our OIT patients successfully reach maintenance.

Are you or someone you love impacted by a tree nut allergy? Take the next step toward better health and better quality of life with Latitude Food Allergy Care. Our Patient Care Coordinators are happy to discuss your testing and treatment options to determine whether you are a candidate for treatment. Contact us today to schedule your no-obligation call.

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