what is a tree nut allergy
A tree nut allergy is an immune response to proteins in tree nuts when it is digested, handled or particles are inhaled. A person can be allergic to one tree nut and not to another, or allergic to all. They can also be allergic to peanuts.
Tree nut allergy can be life threatening and an EpiPen should be carried at all times in case of an emergency. Symptoms usually occur within minutes and can be mild or life threatening. It is common in young children and is less likely to be outgrown.
Tree nut families and types of tree nuts are:
- Walnut: walnuts, pecans
- Mango: Pistachio, cashews
- Beech: beechnut, chestnut
- Birch: hazelnut, filbert, hickory nut
- Plum: almond
There are a few ways that a person with a tree nut allergy may experience a reaction: ingestion, cross-contamination (when tree nuts and peanuts are accidentally included in food during food processing; therefore, food labels often state “may contain nuts” in the ingredient portion), and when particles like tree nut or peanut dust, flour or sprays containing the allergen are inhaled.
Wheezing, difficulty breathing
Runny nose, congestion
Swelling of the lips, eyes, face, tongue and/or throat
Mouth tingles or is itchy
Skin rash (note: eczema is a common skin condition often associated with food allergies, see your doctor for proper diagnosis)
Anaphylaxis (can occur in some severe cases) Anaphylaxis is when the throat swells making breathing difficult because the airways constrict. Other symptoms may include a rapid pulse, dizziness, shock, and lightheadedness. This is life threatening and needs to be treated immediately by a clinician.
A tree nut allergy occurs when the immune system treats a protein in tree nuts as a threat to the body. The immune system uses antibodies to fight the “threatening” substance – the antigen, which is the protein in the tree nut. Immunoglobulin E, or IgE, is an antibody that is produced by the body to attack the food protein (the antigen). Once the antibodies have contact with the antigen it signals an attack on the protein by releasing histamine and other chemicals. These chemicals cause the allergic symptoms.
how to test and diagnose
If you think you have a tree nut allergy track your diet and symptoms. Keep a diary of the foods you are eating and what signs and symptoms you are experiencing after eating those foods.
Remove tree nuts from your diet for 2-3 weeks. Be sure to take out foods that state, “may contain nuts” on the food label. You can use www.foodfacts.com as a guide for ingredients to avoid or for substitutions. After 2-3 weeks gradually reintroduce tree nut products into your diet and see how your body reacts. If your symptoms are relieved during the time the food is eliminated, you may be allergic to that food. See your doctor for proper diagnosis.
Skin Test: See your doctor or an allergist and get tested. Your doctor can perform a skin test. A tiny amount of a food that can possibly cause an allergy is applied to your skin, and then your skin is pricked to allow that amount of food to get below the skin’s surface to see if you have a reaction. If you are allergic a rash may develop or another type of reaction can occur on the area that the food was applied.
Blood Test: A blood test, also called a RAST (radioallergosorbent test) can determine the amount of immunoglobulin E (IgE)antibodies in your blood. Your blood is sent to a lab where they test foods with your blood to see if a particular food causes you have high amounts of IgE. If you have high amounts of IgE then you are allergic to that food.
how to manage
Avoidance is the only way to prevent symptoms from a food allergy. Be careful to read food labels to avoid your allergen and educate yourself on the names of the ingredients that may indicate your allergen is present. There are many substitutions that you can use for the foods you need to avoid.
Wear a Medical Alert bracelet to alert others to be aware of your allergy in case there is an emergency.
Be sure to tell family, friends, co-workers, teachers etc. of your allergy if there should be an emergency.
Carry an epinephrine autoinjector as directed by your doctor. If you have a severe allergy, and in the event that anaphylaxis occurs, this is advisable. This requires a prescription from your doctor. Your doctor may also prescribe other antihistamines. Antihistamines may be used; however, it is not as effective.
ingredients to avoid
- Cashews (butter, flavoring, extract)
- Lichee nut
- Macadamia/Bush nut
- Ginko nut
- Pili nut
- Pine nut/Pinon/pignoli
- Walnut oil
- Almond (butter, paste, extract)
- Hazelnut liqueur
- Frangelico liquer
- Cashew butter
- Pistachio ice cream
- Butter pecan ice cream
- Trout almondine
- Pure almond extract
- Flavoring (check ingredient label)
- Gianduja (chopped nuts mixed with chocolate)
- Nu-Nuts artificial nuts
- Nut meal
- Mashuga nuts
Foods that may contain tree nuts
- Desserts: chocolate, candies, cookies, sweets, pies, brownies, sundaes, ice creams
- Asian foods
- Pesto sauce
- Trail mixes
- Granola bars
- Worcestershire sauce (check ingredient label)
- Suntan lotion (check ingredient label)
- Turtles chocolate
- Cheese spreads
- Specialty coffees
- Hamster/Gerbil food (be cautious if child is handling this food for pets)
Soy nut butter
Tree Nut Allergies
By Victoria Groce, About.com
Updated: June 25, 2008
About.com Health’s Disease and Condition content is reviewed by our Medical Review Board
Content written February 2009, JeanMarie Ceravolo, CHC