Peanut & Tree Nut Allergy

Overview

Peanut and tree nut allergies are among the most well-known and serious food allergies. They often begin in childhood and can last for life, though some children may outgrow them. Both peanuts and tree nuts can trigger reactions ranging from mild rashes to severe anaphylaxis.

What’s the difference?

Peanuts are legumes (same family as peas and lentils).

Tree nuts include almonds, cashews, walnuts, pistachios, pecans, Brazil nuts, macadamias, and hazelnuts.

Some people are allergic to just peanuts or just certain tree nuts. Others may react to several.

Symptoms

Mild to moderate reactions:

Hives or rash
Tingling/itching in the mouth
Swelling of lips, face, or eyes
Tummy pain or vomiting

Severe reactions (anaphylaxis):

Swelling in throat or tongue
Wheezing or breathing difficulties
Sudden dizziness, fainting, clammy skin
Risk of collapse or loss of consciousness

Diagnosis

If nut allergy is suspected, your GP can refer you to a specialist allergy clinic. Testing usually includes:

Skin prick or blood tests
Food challenge tests (under supervision)
Testing across multiple nuts to see which are safe to eat and which to avoid

Living with Nut Allergy

Shopping: Nuts must be clearly labelled in the UK. Always read packaging — even for trusted brands.
Eating out: Ask directly about nut ingredients and cross-contamination.
Cross contact: Mixed nuts, nut butters, nut oils, and certain desserts are common risks.
Air travel: Most airlines don’t guarantee a nut-free environment. Wipe down trays and be cautious with snacks.

Emergency Action

Mild symptoms: antihistamines may help.

Severe symptoms: use adrenaline auto-injector immediately and call 999.

Auto-injectors in the UK include:

EpiPen®
Jext®

Always carry two devices and make sure you and those around you know how to use them.

Outgrowing Nut Allergy

Some children outgrow peanut or tree nut allergies by school age, but many do not. Regular reviews with an allergy specialist can help decide if/when reintroduction is safe.