A hazelnut allergy is a common type of tree nut allergy that usually begins during childhood. Avoiding hazelnuts is the best way to prevent associated allergic reactions.

Tree nut allergies are relatively common, with hazelnuts being among the most prevalent offenders. If you have this type of allergy, you may experience mild to severe symptoms when eating hazelnuts and hazelnut-containing products.

A hazelnut allergy is typically a lifelong condition. Avoiding the tree nut is key to preventing symptoms and potentially life threatening allergic reactions.

Learn more about this type of allergy, including symptoms, causes, and emergency treatment measures.

A hazelnut allergy is a type of food allergy. It’s one of six of the most common types of known tree nut allergies. Other tree nut allergies include almond, walnut, and pistachio, as well as pecan and cashew. Tree nut allergies are common, affecting 0.5% to 1% of people in the United States.

Most cases of tree nut allergies are diagnosed during childhood, after the first year of life, when young children start eating more foods that might contain them.

Hazelnuts come from the Corylus avellana tree. They’re also members of the birch family. The nuts can be eaten raw or toasted, and you can commonly find them in hazelnut-chocolate spreads sold at grocery stores.

When you have a hazelnut allergy, eating any amount of the nuts — including in spreads and recipes — can cause mild to severe reactions.

Symptoms of a hazelnut allergy develop after you’ve eaten the tree nuts directly, or if you’ve eaten other foods contaminated with them.

Some of the most common symptoms include skin itching and hives, along with oral allergy syndrome (OAS).

Symptoms of hazelnut-induced OAS may include swelling and itching around your:

  • mouth
  • tongue
  • lips
  • throat
  • entire face

With OAS, you may experience most symptoms around your face, as this is the area that comes into contact with the food allergen. OAS can also occur with birch pollen and associated cross-reactive foods, including tree nuts like almonds and hazelnuts.

Anaphylaxis is the most severe type of reaction to a hazelnut allergy and is a systemic reaction that can be life threatening. It usually develops within an hour after you’ve eaten the substance you’re allergic to.

Possible symptoms typically involve your airways, and can include:

  • feeling like you have a lump in your throat
  • needing to clear your throat
  • wheezing
  • hoarse voice
  • difficulty breathing

Allergies are triggered by an overreaction by your immune system to specific proteins.

Like other types of food allergies, a hazelnut allergy may cause your immune system to regard the substances as invasive and lead to a whole-body reaction. The resulting symptoms can be mild or severe.

If you’re allergic to hazelnuts, it’s also likely that you might be allergic to other tree nuts, along with birch pollen, due to cross-reactivity.

If you have a previously diagnosed birch pollen allergy and experience OAS symptoms after eating hazelnuts, it can be beneficial to speak with a doctor about a possible hazelnut allergy.

Additionally, researchers believe people who have hazelnut allergies are also more likely to have the following related conditions:

If you have a suspected or confirmed hazelnut allergy, it’s important to avoid these nuts as much as possible, as well as:

  • popular hazelnut-containing food items, such as spreads and dips
  • other types of nuts that may have had possible cross-contamination during manufacturing, such as peanuts
  • hazelnut flavoring agents, such as pastes, extracts, and coffee creamers

While peanuts are technically legumes and not tree nuts, it’s estimated that 30% of people with a peanut allergy are also allergic to tree nuts. You might consider erring on the side of caution and avoiding all nuts unless a doctor says it’s safe otherwise.

When shopping for packaged foods, look for warnings about cross-contamination. By law, food companies must state whether their products contain common food allergens like tree nuts and whether they processed or manufactured them in the same facilities as the allergens.

Ultimately, if you’re in doubt, it’s best to pass on the food in question.

There’s currently no cure for hazelnut allergies. The only way to prevent hazelnut allergies and possible life threatening reactions is to avoid eating the nuts and any items with cross-contamination as best as you can.

However, despite your best efforts, accidental hazelnut consumption can happen. This is why it’s important to keep an epinephrine injection with you at all times, including during work, school, and travel.

Also called an adrenaline shot, this injection is considered a first-line treatment for anaphylaxis from food allergies like hazelnuts, and can be potentially lifesaving if you accidentally eat them.

When to seek emergency medical care

Anaphylaxis is a medical emergency. Most anaphylactic-related deaths occur within the first hour of allergen exposure.

If you do experience anaphylaxis, you should take your epinephrine injection and have someone call 911.

For more mild reactions from accidental hazelnut consumption, a doctor might recommend antihistamines to help alleviate symptoms, and prescription corticosteroids to reduce inflammation from the underlying allergic reaction.

How do you know if you’re allergic to hazelnuts?

Signs that you’re allergic to hazelnuts include symptoms such as skin itching, hives, and oral swelling.

What common foods have hazelnuts in them?

Common foods that have hazelnuts in them include hazelnut-chocolate spreads and dips and hazelnut flavoring agents, such as extracts and coffee creamers.

Can you outgrow a hazelnut allergy?

If you develop a hazelnut allergy as a child, you may outgrow it as an adult. However, an allergist or immunologist would need to confirm this. It’s estimated that only 10% of people with tree nut allergies may outgrow them at some point.

Hazelnut allergies are common types of tree nut allergies that tend to develop during childhood and last throughout your lifetime. Like other types of allergies, these are caused by problems with your immune system, where your body overreacts to proteins in the hazelnuts.

If you have a hazelnut allergy, it’s important to avoid these types of nuts as best as you can. Depending on the severity and possibility of other allergies, a doctor may also recommend you avoid other tree nuts. You will also need to carry an epinephrine shot at all times.

You should talk with a doctor if you’re concerned about a possible hazelnut allergy. They may refer you to an allergist or immunologist for further testing.