If you are allergic to sweet chestnuts, this article should help you understand the basic facts about your allergy. A key piece of advice is to see your GP. If it is suspected that your symptoms could be severe, ask your GP to refer you to an allergy clinic.
Sweet chestnuts are usually simply referred to as chestnuts and so that term will be used throughout this article.
Symptoms caused by allergy to chestnuts
Allergy to chestnuts is uncommon in the UK and this means there is limited information about the potential severity of allergic reactions. Doctors suspect that only a minority of people who are allergic to chestnuts are at risk of a severe reaction; however, it can be difficult to predict those at risk. There may be clues in your medical history. For example, people who suffer from asthma, especially if it is poorly controlled by treatment, are at an increased risk.
Chestnut allergy is most frequently seen in conjunction with allergy to a number of different fruits and vegetables. This is because of something known as “cross-reactivity” – where the proteins in different plants are of a similar structure.
In cases of severe allergy to chestnut, which are rare, the allergen responsible for the reaction is likely to be one of the lipid transfer proteins (LTPs). Symptoms may include wheezing, throat swelling and breathing difficulty and there could even be a fall in blood pressure leading to collapse. The term for this severe form of allergy is anaphylaxis. People affected may have developed allergy to other LTP-containing foods such as peach and apple; and to LTP-containing pollens – especially the pollens of the plane tree and the weed called mugwort (also known as wormwood). Not everyone in this category is at risk of a life-threatening reaction, but it is important to get medical advice.
As stated previously, doctors believe that most people with chestnut allergy experience symptoms that are less severe. In many of these cases, there is also an allergy to Natural Rubber Latex (NRL).
The link with latex – the Latex Food Syndrome
Allergy to latex is a problem that is mainly due to the increased use of latex by the medical profession. Some of the proteins in latex are of a similar structure to those in certain foods, including chestnut. Other foods in this group include avocado, banana, kiwifruit, peach, tomato, potato and sweet pepper. The proteins responsible for this type of allergic cross-reaction are from a protein family known as chitinases.
When people are allergic to both latex and one or more of these foods, the condition is known as Latex Food Syndrome. Sufferers often notice wheezing, itchiness of skin, eyes, nose or mouth when using rubber gloves or blowing balloons. Reactions to the foods are usually mild and not life-threatening and include:
- Redness, swelling or itching of the lips, tongue, inside of the mouth, soft palate and ears
- Itching and swelling of the throat. This is unlikely to prove serious, but in rare cases where the breathing is affected, immediate medical help is needed
- Some people might also experience symptoms in the oesophagus (gullet) or stomach, including pain, nausea and even vomiting
- Sneezing, runny nose, or eye symptoms including itching, redness, puffiness or watering
Medical advice is recommended in all cases of food allergy to determine the level of risk. If it is considered that you are at risk of a severe allergic reaction, self-injectable adrenaline (EpiPen, Emerade or Jext) is likely to be prescribed as well as an antihistamine.
Medical advice is also important in all cases of latex allergy. People who are allergic to latex are at risk during medical and dental procedures, where latex is used. If you are allergic to the foods listed in this section (chestnut, avocado, banana, kiwifruit, peach, tomato, potato and sweet pepper), we advise you to see your GP and ask for an allergy test to latex.
Peanuts and tree nuts
Chestnuts are in a different botanical category to peanuts and also to tree nuts (such as almonds, walnuts, cashews, Brazils). Most people with chestnut allergy can tolerate peanuts and tree nuts. However uncommon exceptions have been reported and some of these cases have been severe. It is important to discuss all this with your doctor.
Where are chestnuts used?
If you are allergic to chestnuts, take special steps to avoid them. Read food labels carefully and always question catering staff very directly when you eat out or buy meals from a takeaway.
Chestnuts are often eaten roasted. They can be used to make stuffing and at Christmas are often served with Brussels sprouts. They are used in baking and can be bought canned, pureed or as chestnut flour. They are sometimes included in game or rich winter casseroles.
Banon is a cheese made in France from unpasteurised goats’ milk, wrapped in brown chestnut leaves and tied with raffia. People who are allergic to chestnuts might react to the leaves although we know of no scientific work to establish this.
Use of chestnuts in cooking in the Far East is widespread so special care is needed if you travel to that region.
Water chestnuts
Water chestnuts, which are common in Oriental cooking, are from a different botanical family to sweet chestnuts (source: Royal Horticultural Society). People who are allergic to sweet chestnuts can normally eat water chestnuts without a problem. In very rare cases where a person is allergic to both, this would be coincidental.
Horse chestnuts (conkers)
People who are allergic to sweet chestnuts often ask if they will react if they handle horse chestnuts. The two are not closely botanically related and we can find no evidence of people with chestnut allergy reacting to conkers.
However, there have been cases of inhalant allergy to horse chestnut pollen and contact dermatitis (a skin rash) caused by handling horse chestnuts. These cases are unrelated to chestnut allergy.
Key messages
- In all cases of food allergy or allergy to latex, a visit to your GP is important. A referral to a hospital allergy clinic may be necessary.
- Severe allergy to chestnut is rare, but if you are in that category, always carry your prescribed treatment everywhere you go.
Read more about latex allergy on Latex Allergy – the Facts on our website.
Read more about anaphylaxis on our website: see Anaphylaxis – the basic facts
Reviewers
This article has been peer-reviewed by Dr Gavin Spickett, Consultant Clinical Immunologist, Royal Victoria Infirmary, Newcastle upon Tyne; and Dr Michael Radcliffe, Consultant in Allergy Medicine, University College London Hospitals NHS Foundation Trust.
Our reviewers report no conflicts of interest in relation to this article.
Our sources
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: Jan 2017
Review date April 2019