The following information is intended to help people with allergy to hazelnuts to manage the condition successfully. The information is intended as general guidance. If you know or believe you are allergic to hazelnuts, it is important to visit your GP and seek a referral to an allergy clinic.
Types of hazelnut allergy
Allergy to hazelnuts can be one of two types.
The first type is considered to be a primary food allergy. A person with this type of allergy will have had previous contact with hazelnuts, resulting in their immune system producing antibodies to hazelnut. This is known as sensitisation. In some of these people, further exposure to hazelnut results in an allergic reaction. This type of allergy has the potential to cause a severe, life-threatening allergic reaction (anaphylaxis), which includes breathing difficulty.
The second type of hazelnut allergy can be considered a secondary food allergy. A person with this type of allergy is initially allergic to tree pollen (usually birch), an important cause of spring hay fever, and then starts reacting to hazelnut. This happens because of a process called cross-reactivity – where a protein found in the pollen has similarities with a protein found in hazelnuts and therefore some people react to hazelnuts. These reactions are usually mild and include itching or swelling in the mouth. The condition is known as pollen food syndrome (previously known as oral allergy syndrome). People affected may also have mild reactions to soft fruits but tolerate them in the cooked form.
It is important that you know which of the two types of hazelnut allergy you are affected by. It is possible to have a primary hazelnut allergy and pollen food syndrome. Ask your GP to refer you to an allergy clinic so that a proper diagnosis can be performed.
Avoiding other types of nuts
Some people who are allergic to one type of nut may become allergic to others. There is also the possibility of certain nuts coming into contact with others during food production. So, is it best to avoid all nuts if you are allergic to one or two of them?
Some allergy experts would indeed advise that total avoidance is best in order to play safe. But others disagree. One study states: “In peanut or tree nut allergic children, introduction of specific nuts to which the child is not allergic may improve quality of life and should be considered in patients with multiple foods allergies, vegan or ethnic-specific diets, in whom nuts are an important source of protein.”
Our advice is that it depends what tests you have had. If you have been tested for specific nuts, your GP or allergist will be able to advise whether it is possible to include certain nuts in your diet. If you do eat specific nuts, it is usually advisable to do so at home so you can better control any risk of cross-contamination. Eating nuts from the shells avoids the risk of cross-contamination from other nuts.
If you have not been tested for specific nuts, then we believe in playing safe — avoiding all nuts — until you are able to be tested
Hazelnuts – also known as filberts or cob nuts – can be found in various food products including biscuits, cakes, pastries, chocolates, chocolate spread, confectionary products, breakfast cereals and bread. Praline chocolates and nougat are two confectionary products to watch out for.
Hazelnut oil can be used in baking or in a salad dressing. Hazelnut butter is sold in some supermarkets and health food shops. Hazelnut ‘milk’ is now a popular alternative to cow’s milk. There has also been a recent increase in hazelnut ice cream products.
In Europe hazelnuts are made into liqueurs of which the best known is Frangelico Hazelnut Liqueur.
Hazelnuts are also ground and may be used to produce ethnic products such as:
- Dukkah is a spicy dry dip – bread is dipped into it and then into olive oil and eaten; it can also be used as a seasoning mix.
- Za’atar is a mixture of sesame seeds, herbs and spices to which hazelnuts may sometimes be added to create a varying flavour. It is mixed with oil and sprinkled over a variety of items including salads, soups and white cheese.
Like peanut oil, hazelnut oil is thought to be low risk if it is highly refined. However, the oil is normally used for its flavour and so should be assumed to be unrefined.
As well as being used in baking it is also suitable and used for purposes such as shallow frying fish, especially trout.
This article has been reviewed by Dr Gary Stiefel, Consultant in Paediatric Allergy, University Hospitals of Leicester NHS Trust. He reports no conflicts of interest.
All the information we produce is evidence based or follows expert opinion and is checked by our clinical and research reviewers. If you wish to know the sources we used in producing any of our information products, please let us know, and we will gladly supply details.
Publication date: October 2019
Review date: October 2022