What is a Tree Nut Allergy?

A tree nut allergy is an allergic reaction to one or more types of tree nuts. Your immune system mistakenly attacks certain proteins in tree nuts causing the symptoms of an allergic reaction. Tree nut allergies are one of the most common food allergies for both children and adults.

Symptoms

Allergic reactions to tree nuts can be mild or severe. Tree nut allergy symptoms may occur immediately after exposure to tree nuts or may occur in the next few hours after exposure.

Common signs and symptoms of a tree nut allergy include:

• Stomach pain
• Stomach cramps
• Upset stomach
• Vomiting
• Nausea
• Diarrhea
• Runny nose
• Nasal congestion
• Wheezing
• Itchy mouth
• Itchy skin
• Itchy eyes
• Itchy hands

The two most common symptoms of a tree nut allergy are abdominal pain and nausea/ vomiting. Some individuals with this condition will experience a tree nut allergy rash. A serious tree nut allergy reaction that requires urgent medical care is anaphylactic shock.

This symptom usually occurs immediately after exposure to tree nuts and is potentially life threatening. Trouble swallowing, a swollen throat, wheezing, trouble breathing, and passing out are all signs of anaphylactic shock. Since this is an urgent medical emergency, if you or anyone you love experiences the symptoms of anaphylactic shock, please seek medical care immediately.

Causes

You experience tree nut allergies when your immune system recognizes certain proteins in tree nuts as harmful substances or threats. To protect your body, your immune system releases histamine, a chemical that causes the symptoms of an allergic reaction. The six most common tree nut allergies are hazelnut, walnut, pecan, almond, pistachio, and cashew. A tree nut allergy is sometimes also referred to as a walnut allergy, cashew nut allergy or pecan allergy.

The following tree nuts and ingredients can cause a tree nut allergic reaction:

• Almond
• Walnut
• Pecan
• Pistachio
• Cashew
• Pili nut
• Chestnut
• Praline
• Artificial nuts
• Beechnut
• Brazil nut
• Shea nut
• Ginkgo nut
• Hickory nut
• Nangai nut
• Pine nut
• Butternut
• Chinquapin nut
• Coconut
• Marzipan/almond paste
• Filbert/hazelnut
• Nut butters
• Litchi/lichee/lychee nut
• Macadamia nut
• Black walnut hull extract
• Natural nut extract
• Walnut hull extract
• Nut distillates/alcoholic extracts
• Nut meal
• Nut paste
• Nut meat
• Nut milk
• Nut oils
• Nut pieces
• Pesto
• Gianduja, a mixture of chocolate and nut

Peanuts are not considered a tree nut. They are actually considered legumes. Other foods and food items, such as coconut and nutmeg, contain the word “nut” but are not botanical nuts.

Diagnosis

Tree nut allergy diagnosis involves a routine physical exam along with additional tests to confirm the diagnosis. During these tests, your doctor will look for immunoglobulin E, which is an antibody that attaches to allergens and prompts the release of histamine. Histamine is responsible for the allergic reaction symptoms.

Tree nut diagnostic tests can include:

• Skin prick test – This test involves your doctor slightly pricking your skin and exposing the small area to a sample of tree nuts. If you have a tree nut allergy, typically the exposure will cause a rash or other reaction on your skin.
• Blood test – Doctors will measure how your immune system reacts to tree nuts. They will be looking at the amount of immunoglobulin E (IgE) antibodies in your blood, which can indicate a possible tree nut allergy.
• Oral food challenge – An allergy specialist provides you with food items that contain tree nuts. The specialist will closely watch you for signs and symptoms of an allergic reaction.
• Food tracking and elimination – Your doctor may ask you to keep a diary or to otherwise track the food you eat every day.

Children with a tree nut allergy sometimes grow out of the condition. Adults with a tree nut allergy will likely have the condition for life. The general prognosis for a person with a tree nut allergy depends on the severity of the allergy. Increased awareness of food allergies and clearer food labeling can help anyone with the condition avoid allergic reactions.

Management & Treatment

The best way to prevent a tree nut allergy is to avoid foods and food items that contain tree nuts or tree nut ingredients. There is no tree nut allergy cure, but there are several tree nut allergy treatments to help you manage your condition.

Common prevention and management options include:

• Read food labels to avoid accidently exposing yourself to tree nuts or tree nut ingredients. Companies sometimes change ingredients and recipes, so we recommend that you check food labels regularly. 
• Carry an emergency epinephrine auto-injector to address severe allergic reactions such as anaphylactic shock that can be potentially life threatening.
• Discuss your allergy with restaurant servers, chefs, friends, family, and anyone else who may be preparing a meal for you.
• Check the ingredients in shampoos, conditioners, lotions, and anything else that comes in contact with your skin. These products sometimes include ingredients that can trigger an allergic reaction.

If you or a loved one experiences any of the signs of a tree nut allergy, please contact an allergy specialist with Baptist Health today.