Hazelnut allergy: symptoms, diagnosis and treatment

Walnuts are nuts that grow on trees. They include Brazil nuts, cashews, walnuts, pecans, pistachios, and hazelnuts. Hazelnut allergy is one of the most common tree nut allergies, affecting 0.2% to 0.5% of people in the United States.

This article explains where hazelnuts are found and what kinds of symptoms an allergic reaction can cause. It will also explain how hazelnut allergy is diagnosed and how you can manage it if you have this allergy.

Where are the hazelnuts

Hazelnuts can grow almost anywhere in the continental United States.

You will find hazelnuts:

  • Packed by themselves
  • In mixed nut snacks
  • In cookies and chocolates
  • With nut oils
  • In confectionery like praline
  • In chocolate spreads like Nutella
  • With Frangelico hazelnut liqueur

Hazelnut Allergy Symptoms

With a hazelnut allergy, symptoms usually occur soon after or immediately after eating hazelnuts or foods containing them.

Possible reactions, from least to most serious, include:

  • Nasal congestion or runny nose
  • Wheezing or coughing
  • Itching of the mouth, throat, eyes, skin or any other area
  • Urticaria
  • Nausea, abdominal pain, vomiting or diarrhea
  • Difficulty swallowing
  • Shortness of breath
  • Swelling of the lips, tongue, or face (called angioedema)

Anaphylaxis

Anaphylaxis is a severe, life-threatening allergic reaction that comes on suddenly, making it difficult to breathe and can cause shock. Nut allergies are among those commonly associated with anaphylaxis. Anaphylaxis is a medical emergency.

Causes and risk factors

Nut allergies usually begin in childhood. People with a family history of allergies are at higher risk of developing a nut allergy. Nut allergies are also associated with eczema and asthma.

These allergic reactions occur when the body’s immune system reacts to hazelnuts as if it were a harmful substance. This immune response produces the symptoms.

Oral allergy syndrome

One type of allergic reaction, oral allergy syndrome (OAS), also known as pollen food allergy syndrome, is a form of food allergy in which people who are sensitive to specific types of pollen also react to certain related foods. to these pollens.

Many people with a birch pollen allergy also react to hazelnuts. Birch pollen contains allergens similar to substances found in hazelnuts, so the body reacts to both.

Symptoms of oral hazelnut allergy syndrome are usually quite mild and are limited to:

Occasionally, some people with OAS have more serious reactions which may include:

  • Rashes
  • Swelling of the lips, tongue and throat
  • Delayed gastrointestinal symptoms (abdominal cramps, diarrhea)

Anaphylaxis is very rare in people with OAS.

Peanuts are not tree nuts. They grow underground and are legumes. About 25-40% of people with a peanut allergy are also allergic to at least one type of nut.

Diagnostic tests

In order to diagnose a hazelnut allergy, an allergist will take your medical history and ask you about the timing of your symptoms. They will also ask if you or your family members have any other allergies.

The allergist will likely perform a skin test.

A blood test can detect the presence of immunoglobulin E (IgE), an antibody that binds to allergens and triggers the release of chemicals that cause symptoms.

Results interpretation

An IgE blood test that detects higher than normal IgE levels indicates an allergy, but it cannot identify the allergen.

During a skin test, a small amount of the allergen found in hazelnuts is applied below the surface of your skin. If you develop hives (also called weals) or another reaction, it could indicate a hazelnut allergy. A skin test reaction of 3 mm papule (hive) larger than the negative control is considered positive, which means that you are probably allergic to the substance that was injected. Size of skin test reaction does not correlate with severity of clinical reaction

If these tests are inconclusive, your allergist may recommend an oral food challenge. During this test, you will eat small amounts of food in increasing doses over a period of time. This should be done under supervision in an allergist’s office as there is a risk of a serious reaction.

Treating Hazelnut Allergy

Symptoms of OAS can be treated with an over-the-counter antihistamine such as Benadryl.

There is no cure for hazelnut allergy. The only way to avoid a reaction is to avoid eating nuts.

Nuts are one of the eight most common food allergies in the United States and are covered by current food allergy labeling laws. Food manufacturers are required to list nuts on their plain language ingredient labels. This makes nuts quite easy to avoid in packaged foods.

A hazelnut allergy warning on an ingredient label should look like this: “Contains tree nuts (hazelnuts).”

If you are prone to an anaphylactic reaction, your health care provider will prescribe an epinephrine auto-injector (commonly called an EpiPen). You will need to have your auto-injector with you at all times so that it is always available in the event of a severe reaction.

Summary

Hazelnut allergy is one of the most common tree nut allergies. This nut is commonly used in cookies, chocolates and pastries.

With oral allergy syndrome, which causes people with pollen allergies to react to other substances (such as hazelnuts), reactions are usually mild. However, for those particularly sensitive to the hazelnut allergen, there is a risk of more serious reactions, including anaphylaxis, which is a medical emergency. An allergist can perform a variety of tests to confirm a diagnosis of hazelnut allergy.

A word from Verywell

Hazelnuts are an ingredient in many foods and desserts. Talk to your healthcare provider or allergist if you notice any symptoms after eating or touching hazelnuts. You may need to do allergy testing to determine if you are allergic to hazelnuts and also if you have allergies to other nuts.

When ordering food at a restaurant, stay safe by telling your server or asking to speak to the chef about your hazelnut allergy.

Frequently Asked Questions


  • Can children overcome nut allergies?

    Tree nut allergies usually persist throughout a person’s lifetime. However, about 10% of people with a nut allergy may outgrow the allergy over time.


  • Should you avoid all forms of hazelnut if you are allergic?

    You should avoid anything that you know contains real hazelnuts. Some hazelnut flavored products, such as coffee, may not contain the hazelnut allergen. To be on the safe side, you should always ask your server or contact the manufacturer to be sure.


  • Can you eat hazelnuts if you are allergic to peanuts?

    About 25% to 40% of people with a peanut allergy are also allergic to at least one type of nut. The best way to know if you are allergic to hazelnuts is to take an allergy test.


  • Does hazelnut coffee contain nuts?

    In general, coffee and other nutty flavored products do not contain the hazelnut allergen, but the only way to be sure is to contact the manufacturer.

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