Nut Allergy

Nut allergy

Nut allergies are the most common and often the most severe type of food allergy. While they can make a healthy snack, eating these small fruits can be life-threatening for some people. Today we’re going to look at what causes a nut allergy reaction , what symptoms you might expect, what types of nuts you may react to, and how to tell if you have a nut allergy or intolerance. Let’s get stuck into it.

What is a nut allergy?

A nut allergy is an adverse and potentially harmful reaction to nuts. If you have an allergy to nuts, your immune system mistakenly believes that nuts are dangerous, and it mounts an attack against them. 

The first time you are exposed to nuts, you may not experience a nut allerfy reaction. However, your immune system creates special molecules (called IgE antibodies) to alert its defences every time you are exposed to nuts in the future. So when you touch or eat a nut the next time, your body reacts by releasing chemicals like histamine. Histamine causes the symptoms of allergy, which are highlighted for you below.

Symptoms of nut allergy

A nut allergy reaction may include:

  • skin rashes or hives
  • swollen, raised, red, or sensitive skin
  • a stuffy or runny nose
  • sneezing
  • watery, itchy, or swollen eyes
  • tingling of the tongue or throat
  • nausea
  • stomach cramps
  • vomiting
  • diarrhoea

Tree nuts and peanuts are some of the most dangerous foods when it comes to severe allergic reactions known as anaphylaxis. Anaphylaxis is life-threatening and requires immediate medical attention. 

The symptoms of anaphylaxis include: 

  • swelling of your face (including your lips, tongue or throat)
  • noisy or laboured breathing
  • a tight throat or hoarse voice
  • difficulty talking
  • wheezing 
  • coughing
  • an abnormal drop in blood pressure
  • increased pulse
  • dizziness
  • confusion or loss of consciousness

Types of nuts you can be allergic to

If you have an allergy to one type of nut, there is a high likelihood that you will be allergic to other kinds of tree nuts as well. The types of tree nuts that you can be allergic to include:

  • almonds
  • cashews
  • pistachios
  • walnuts
  • pine nuts
  • pecans
  • macadamia nuts
  • hazelnuts
  • Brazil nuts

Peanuts are also a common allergen. However, while their name includes the word ‘nut’, peanuts are not a nut but a legume. Although they are not a tree nut, you can have a similar allergic reaction to peanuts as you would a tree nut. If you are allergic to peanuts, there is a 25-40% chance of you also having a tree nut allergy. Coconut, much like peanuts, is also not a nut but a large seed. Having an allergy to coconut is rare.

Nut allergies can occur after contact with just a tiny amount of nuts (like less than one nut) or even a trace of nuts. You don’t necessarily have to eat the nuts to have a reaction; you might simply stand next to someone eating nuts or put the tiniest amount to your lips.

The difference between nut allergy and nut intolerance

A nut allergy is a very different reaction to a nut intolerance. As we’ve learnt, a nut allergy is caused by an immune response to nuts. The nuts can be in the environment or in your food. When you have a nut intolerance, your gut reacts to the nuts because you are not digesting them properly. This also means that you must actually eat the nut to have symptoms.

The symptoms of nut intolerance take place mainly in the gut because it is a digestive issue. This includes:

  • bloating
  • tummy aches
  • stomach cramps
  • gas
  • nausea
  • diarrhoea

Other symptoms of nut intolerance include itchy skin, acne, tiredness, and a runny nose. 

The symptoms of nut intolerance tend to be delayed. You can experience them within an hour of eating nuts, but they can take up to three days to appear. This is different to a nut allergy, which often happens within minutes to hours of being exposed to nuts.

Testing for nut allergy and intolerance

If you suspect that you have a nut allergy, you can speak with your doctor about your symptoms and allergy testing. Your doctor may then refer you to an allergy specialist known as an allergist or immunologist. To test for an allergy to nuts, you may:

  • have a blood test (which measures the IgE antibody)
  • do a skin prick test (which shows your skin’s reaction to nuts)
  • complete a food challenge (which involves avoiding all nuts and then reintroducing them while under the supervision of a medical practitioner)

If you suspect that you have a nut intolerance, you can test for it with our food intolerance test. It is a simple test with a fast turnaround. Simply order the test HERE, and send our lab your hair sample. Within three days of receiving your sample, you will have your results!


Today we learnt all about nut allergy. We discovered that it is an immune reaction in which your body releases a chemical called histamine. The histamine is responsible for all the allergy symptoms, such as skin rashes, swelling, sneezing, and the severe manifestations of anaphylaxis. We delved into the term ‘nut allergy’ and how it’s often used to describe an allergy to tree nuts, peanuts (a legume), and coconut (a seed). We then explored the different types of testing that can be done for a nut allergy, as well as the testing you can do for a nut intolerance – which can be ordered HERE. Finding out whether you have a nut allergy or a nut intolerance can help you resolve it and may even be a life-saver.

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