Tree nut allergy facts for kids

Quick facts for kids Tree nut allergy
Hazelnuts, a type of tree nut
Similar conditions	Peanut allergy

A tree nut allergy happens when your body's defense system, called the immune system, overreacts to certain tree nuts. This can cause serious physical symptoms. Tree nuts include many different kinds, like almonds, Brazil nuts, cashews, chestnuts, hazelnuts, macadamia nuts, pecans, pistachios, shea nuts, and walnuts.

The best way to manage a tree nut allergy is to avoid eating tree nuts and foods that have them. If someone accidentally eats a nut, they need quick treatment. It can be tricky to avoid nuts completely because not all countries require food labels to say if there are tiny amounts of allergens in food.

A tree nut allergy is different from a peanut allergy. That's because peanuts are legumes (like beans or peas), while tree nuts are hard-shelled fruits from trees.

What Are the Symptoms of a Tree Nut Allergy?

Signs and symptoms of anaphylaxis

When someone has a food allergy, symptoms usually appear quickly, from a few minutes to a few hours after eating the food. This quick reaction is called an IgE-mediated response. It can sometimes lead to a very serious reaction called anaphylaxis.

Common symptoms can include:

• Rashes or hives (itchy bumps on the skin)
• Itching in the mouth, lips, tongue, throat, eyes, or skin
• Swelling of the lips, tongue, eyelids, or face
• Trouble swallowing
• A runny or stuffy nose
• A hoarse voice
• Wheezing or shortness of breath
• Diarrhea or stomach pain
• Feeling lightheaded or fainting
• Nausea or vomiting

Less severe reactions can happen hours or even days after eating the food. These are called non-IgE-mediated responses. Symptoms can be different for each person and each time a reaction happens.

A very serious, life-threatening reaction is anaphylactic shock. This happens when the body's immune system releases chemicals that cause severe symptoms all over the body. Signs of anaphylaxis include:

• Trouble breathing, like wheezing or gasping
• Blue-ish skin (called cyanosis)
• A weak pulse
• Pale skin
• Fainting

If not treated quickly, anaphylaxis can cause blood pressure to drop dangerously low. Eating raw nuts often causes a more serious reaction than eating roasted nuts or nut oils. This is because processing can sometimes reduce the strength of the allergy-causing proteins.

How Do Doctors Diagnose a Tree Nut Allergy?

If you think you might have a tree nut allergy, it's important to see an allergist right away. An allergist is a doctor who specializes in allergies. They can perform tests to find out exactly what you are allergic to. Tree nut allergies can sometimes run in families.

Doctors often use these tests:

• Skin-prick tests: A tiny amount of nut protein is placed on your skin, and the skin is gently pricked. If you're allergic, a small red bump will appear.
• Blood tests: These tests look for special antibodies called immunoglobulin E (IgE) in your blood. These antibodies are released when your body reacts to allergens.

If the test results are not clear, your doctor might suggest an oral food challenge. This test involves eating tiny amounts of the suspected food while under the direct supervision of the allergist. This is done in a safe medical setting in case a reaction occurs.

How Can You Prevent Allergic Reactions?

The best way to prevent a reaction is to completely avoid foods that contain tree nuts. This means being very careful about what you eat. In the United States, a law called the Food Allergen Labeling and Consumer Protection Act (FALCPA) requires packaged foods to clearly list if they contain tree nuts.

Foods that often contain tree nuts include:

• Pesto
• Marzipan
• Nutella
• Baklava
• Pralines
• Nougat
• Gianduja
• Turrón

Other common foods that might have tree nuts are cereals, crackers, cookies, baked goods, candy, chocolates, energy bars, flavored coffee, frozen desserts, marinades, barbecue sauces, and some cold cuts. Tree nut oils are also sometimes found in lotions and soaps. Places like Asian and African restaurants, ice cream shops, and bakeries can be risky. This is because they often use nuts, and there's a chance of cross-contamination. Cross-contamination means tiny bits of nuts could get into other foods.

Cross-Reactivity: What Does It Mean?

Sometimes, if you're allergic to one type of tree nut, you might also react to other tree nuts. This is called cross-reactivity. It happens because the proteins in different nuts can be very similar. People with a confirmed tree nut allergy might react to more than one type of tree nut. For example, allergies to almonds, walnuts, pecans, hazelnuts, and Brazil nuts are often linked. However, these are less likely to cross-react with cashews or pistachios.

Because of cross-reactivity, people with a tree nut allergy are often advised to avoid all tree nuts. This is a safety measure, even if they haven't reacted to every single type of nut.

What Is the Outlook for Tree Nut Allergies?

Tree nut allergies tend to be lifelong. Studies show that only about 9% of children outgrow their tree nut allergy.

How Are Tree Nut Allergies Treated?

Epinephrine autoinjectors are portable single-dose epinephrine-dispensing devices used to treat anaphylaxis.

The main treatment for a tree nut allergy is to strictly avoid the nuts you are allergic to. If someone accidentally eats nuts, the treatment depends on how sensitive they are.

• For mild reactions, an antihistamine like diphenhydramine might be given.
• Sometimes, a medicine called prednisone is prescribed to prevent a delayed allergic reaction.
• For severe allergic reactions (anaphylaxis), an epinephrine pen is used. This is a special injection device that can be used by anyone, even if they are not a healthcare professional, to give emergency treatment.

How Are Foods Regulated for Allergies?

Awareness about food allergies has grown a lot. This has changed how children, parents, and caregivers live. In the United States, the Food Allergen Labeling and Consumer Protection Act (FALCPA) was put into law in 2004. This law means that food packages must remind people about allergy problems. Restaurants have also started adding allergy warnings to their menus.

Cooking schools, like The Culinary Institute of America, now teach chefs how to cook without allergens. Schools also have rules about what foods can be brought in. Even with all these precautions, people with serious allergies know that accidental exposure can still happen at friends' houses, at school, or in restaurants.

Food Labeling Rules

Many countries have laws that require food products to clearly state if they contain major allergens. This helps consumers with allergies. However, most countries do not require labels to say if there are tiny "trace amounts" of allergens due to cross-contamination. Brazil is one of the few countries that does require this.

Ingredients Added on Purpose

FALCPA in the U.S. requires companies to list eight major food allergens if they are intentionally added to packaged food. These are: cow's milk, peanuts, eggs, shellfish, fish, tree nuts, soy, and wheat. If an ingredient comes from one of these allergens, it must be clearly stated. For example, "Casein (milk)" or a separate "Contains milk" statement. The European Union has similar rules but includes even more allergens.

FALCPA applies to packaged foods regulated by the FDA. It does not cover most meats, poultry, or alcoholic drinks. Also, it does not apply to food prepared in restaurants. However, some countries, like those in the EU, require restaurants to provide allergy information for unpackaged food.

Tiny Amounts from Cross-Contamination

Labeling for tiny amounts of allergens from cross-contamination is a tricky topic. This happens when allergens accidentally get into food during processing or packaging. Experts are working to agree on clear rules for this. They want to know which foods need labeling, how much allergen is too much, and how to test for these tiny amounts.

Some countries have "may contain" warnings, also known as precautionary allergen labeling (PAL). This can be confusing because the wording varies a lot. Some countries, like South Africa, only allow "may contain" labels if manufacturers can prove the risk of cross-contamination. Other groups are working on guidelines to help food makers decide when to use these warnings.

In Brazil, since 2016, it is mandatory to declare the possibility of cross-contamination. This applies if a product does not intentionally contain allergens but good manufacturing practices cannot fully prevent accidental trace amounts. This rule covers many allergens, including wheat, eggs, fish, peanuts, milk, and many tree nuts.

How Tree Nut Allergies Affect People's Lives

Living with a food allergy can greatly affect a person's quality of life. For children with allergies, it can also lead to bullying. This can include threats or even actions like being touched with foods they need to avoid. Sometimes, their allergen-free food is even deliberately contaminated.

What New Research Is Happening?

Scientists are working on new treatments for tree nut allergies. These treatments are called immunotherapy. They include:

• Oral immunotherapy: Eating tiny, increasing amounts of the allergen.
• Sublingual immunotherapy: Placing tiny amounts of the allergen under the tongue.
• Epicutaneous immunotherapy: Using a patch on the skin that contains the allergen.