What is a nut allergy?

Nut allergy is a condition where the body reacts abnormally to the harmless proteins naturally present in nuts. The immune system ‘attacks’ the nut proteins, setting off a chain of reactions that release natural chemicals in the body, as it mistakes the proteins as a threat to the body.


According to BSACI, nut allergy affects around 2% of children and 0.5% of adults in the UK.

Signs & symptoms of a nut allergy – what to look for

Signs and symptoms of peanut and ‘tree nut’ allergy vary; some appearing in a matter of minutes after contact with nuts and others up to an hour or two later. Symptoms can be mild, moderate, and sometimes can be severe and even life-threatening.

The most common mild to moderate symptoms include:

  • Blotchy raised or itchy ‘nettle’ rash
  • Itchy mouth, tongue or throat
  • Swelling of lips, eyes or face
  • Runny nose and sneezing
  • Vomiting, tummy ache and diarrhoea

Severe symptoms include:

  • Difficulty breathing, wheezing or a persistent cough
  • Swelling of tongue or throat
  • Throat tightness
  • Drowsiness

Anaphylaxis is the most severe allergic reaction and can be life-threatening.

Types of nuts

It is possible to be allergic to peanuts but not to tree nuts, or vice versa, or to both.

  • Peanuts are actually legumes that grow (like garden peas, chickpeas and lentils)
  • Tree nuts include cashew, hazelnuts, almonds, walnuts, pistachio, macadamia, pecan and Brazil nuts.

Nut allergies in children vs. adults – can kids outgrow a nut allergy?

  • Nut and peanut allergy usually develops in early childhood, under the age of three.
  • Sometimes children outgrow their food allergy by the age of 5 but nut and peanut allergies tend to persist for years and into adulthood.
  • For some people, nut allergy can appear later in life.

How to get a diagnosis

It’s very important to get a professional diagnosis of any food allergy. The first step should be to contact your GP, who will check out symptoms and refer you on to a specialist allergy clinic for testing with skin prick tests or blood tests. You might find it helpful to keep a diary of symptoms, but don’t cut out foods until you have proper diagnosis as this could cause nutrient deficiencies.

What to do if you have a peanut or nut allergy

After a nut or peanut allergy is confirmed, the first line of treatment is usually to avoid them as there is no cure.

  • When shopping, always read food labels. Find out all of the names for nuts and look out for these on food labels and ingredients lists, e.g. peanuts can also be known as beer nuts, groundnuts and monkey nuts
  • Nut oils are usually refined, but it’s recommended that these are avoided to as there may be a trace of nut protein
  • When eating out, food outlets should be able to provide a list of food allergens in their products. It’s best to always notify the staff about any nut or peanut allergy so that they can ensure the food is safe and not contaminated with any nuts
  • If a label states ‘may contain nuts / peanuts’ it’s safest to avoid them as it may be contaminated by nuts
  • Take care with any foods that are not labelled, or anything suspicious, and if you are unsure whether they contain nuts or nut products it’s best to avoid them
  • NB Some non-foods may contain nut traces, such as tree nut oil soap or shampoo
  • Medications: For those with mild or moderate allergic reactions, antihistamines can be used to relieve symptoms. However, as a food allergy can cause some severe and life-threatening reactions, the allergy clinic may prescribe an adrenaline auto-injector ‘pen’ for use in an emergency, and this should always be kept in easy reach.

For more information about food allergies, visit anaphylaxis.org.uk and allergyuk.org

Try one of our nut-free recipes

Always check ingredients on packaging before using.

Creamy tarragon chicken bake
Mixed bean goulash
Lazy cheesy vegetable hotpot
Chocolate crunch & raspberry pots
Summer pudding trifles

This article was published on 25 March 2021.

Dr Frankie Phillips is a registered dietitian and public health nutritionist specialising in infant and toddler nutrition with over 20 years’ experience.


All health content on bbcgoodfood.com is provided for general information only, and should not be treated as a substitute for the medical advice of your own doctor or any other health care professional. If you have any concerns about your general health, you should contact your local health care provider. See our website terms and conditions for more information.

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