Allergy
Peanut Allergy: What You Need to Know
A practical guide to symptoms, avoidance, adrenaline auto-injectors, written action plans, school safety, and emergency warning signs.
Patient information page | Last reviewed: June 2026
The quick answer
Peanut allergy happens when the immune system reacts to peanut protein as if it is harmful. Some reactions are mild, but peanut allergy can sometimes cause anaphylaxis, which is a life-threatening allergic reaction. People at risk should know their symptoms, avoid peanuts carefully, and carry emergency medicines if prescribed.
Printable resource: Keep a written action plan with medicines, school information, travel documents, or care instructions.
Download the printable action planPeanut allergy can cause allergy chemicals to be released in the body. Histamine is one of these chemicals. Reactions can happen quickly after exposure, sometimes within minutes.
See also: How to recognize anaphylaxis and use an adrenaline auto-injector.
Symptoms of a peanut reaction
Mild or moderate symptoms may include hives, itching, flushing, swelling of the lips or face, tummy pain, vomiting, or feeling unwell.
Treat it as an emergency if there are symptoms affecting the airway, breathing, circulation, or alertness.
Airway
Swollen tongue or throat, tight throat, difficulty swallowing, or a hoarse voice.
Breathing
Wheeze, persistent cough, noisy breathing, chest tightness, or shortness of breath.
Circulation or brain
Dizziness, faintness, collapse, confusion, severe drowsiness, or a pale and floppy child.
Do not wait for a rash before treating serious breathing, throat, collapse, or severe drowsiness symptoms.
1. Avoid peanuts
The main treatment for peanut allergy is avoidance. Peanut allergy can sometimes cause a reaction after a very small amount, so people with confirmed peanut allergy are usually advised to avoid peanuts strictly.
Obvious sources
Avoid foods such as peanut butter, peanut sauces, satay, peanut flour, crushed peanuts, and foods cooked or served with peanuts.
Hidden sources
Check ingredient labels every time. Peanuts may be found in biscuits, cereals, chocolate, sweets, desserts, sauces, and ready meals.
Cross-contact
Food can come into contact with peanut during preparation, storage, or serving. This can happen in bakeries, buffets, restaurants, shared kitchens, and food factories.
Eating out
Clearly tell staff that you have a peanut allergy and ask how the food is prepared.
Label advice
If a label says “may contain peanuts” or “made in a factory that handles peanuts,” avoid it unless your allergy doctor has given you specific different advice.
2. Carry two adrenaline auto-injectors
People at risk of anaphylaxis are usually advised to carry two in-date adrenaline auto-injectors at all times.
For children, this means the devices should be available at home, school, childcare, travel, and activities.
- The first dose may not be enough.
- Symptoms may continue or return.
- The device may misfire.
- The first dose may be used incorrectly during panic.
Practise with a trainer device so the child, parents, school staff, and carers know what to do.
3. Use adrenaline first in anaphylaxis
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Use the adrenaline auto-injector immediately if there is trouble breathing, throat tightness, a hoarse voice, collapse, severe drowsiness, or sudden faintness after possible peanut exposure.
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Call emergency services and say “anaphylaxis”. Adrenaline should not be delayed while waiting to see if symptoms settle.
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Use the second auto-injector after 5 minutes if symptoms have not improved or are getting worse. Use a different injection site if possible.
Antihistamines are not enough for anaphylaxis
Antihistamines may help itching or hives, but they are not a substitute for adrenaline when anaphylaxis is suspected.
4. Have a written allergy action plan
A written allergy action plan helps parents, school staff, relatives, and emergency responders know exactly what to do.
What to include
The child’s name and allergy, symptoms to watch for, when to use adrenaline, where the auto-injectors are kept, emergency contacts, and the doctor’s instructions.
Where to keep it
Keep copies with medicines, at school or childcare, during travel, and with anyone who regularly looks after the child.
5. School, childcare, and travel planning
- Make sure school or childcare staff know about the allergy.
- Make sure staff know how to use the adrenaline auto-injector.
- Keep medicines accessible. They should not be locked away where they cannot be reached quickly.
- For travel, carry safe snacks and check food labels carefully.
- Keep auto-injectors in hand luggage or somewhere immediately accessible.
Important note about other nuts and foods
Do not remove other nuts or major food groups unless your doctor has advised this. Some people with peanut allergy can eat certain tree nuts safely, while others need to avoid them. This should be discussed with an allergy doctor, because unnecessary avoidance can make diet more restricted than needed.
When to seek urgent help
Call emergency services immediately if there is difficulty breathing, throat tightness, swelling of the tongue or throat, hoarse voice, collapse, faintness, severe drowsiness, or rapidly worsening symptoms after possible peanut exposure.