What is a peanut allergy?

A peanut allergy is when eating a small amount of peanut triggers an allergic reaction. Very sensitive people can also have a reaction (usually mild) if they:

• are exposed to tiny traces of peanuts in the air
• touch a peanut

A severe reaction — anaphylaxis — can be life threatening.

Tree nut allergies are also common, but peanuts are legumes, not nuts. If you're allergic to peanuts, you won't necessarily be allergic to tree nuts.

What are the symptoms of a peanut allergy?

A mild allergic reaction to peanut may cause symptoms such as:

• hives or welts
• swelling around your mouth
• vomiting, abdominal pain or diarrhoea

Even if you have only ever had a mild allergic reaction to peanuts, you may still have a risk of having anaphylaxis (severe allergic reaction).

Symptoms of anaphylaxis are:

• difficult or noisy breathing
• swollen tongue
• swollen, tight throat
• difficulty talking or a hoarse voice
• wheezing or persistent coughing
• dizziness
• collapse

Young children may become pale and floppy.

What causes a peanut allergy?

A peanut allergy develops when your body's immune system becomes over-sensitive to a protein found in peanuts. Exposure to peanuts, usually through eating them, causes an allergic reaction.

Food allergies are more common in people who have other allergic conditions such as hay fever, asthma or eczema.

When should I see my doctor?

You should see your doctor if you:

• think you or your child have experienced symptoms of peanut allergy
• have questions or concerns about introducing peanuts into your baby's diet
• do not have an allergy action plan and have ever had symptoms of a food allergy

If you or your child have severe symptoms, you should seek emergency treatment.

How is peanut allergy diagnosed?

If you suspect that you or your child have reacted after eating peanuts, the first step is to see your doctor. They will examine you and ask questions about what has happened.

They may send you to an allergy specialist for a skin-prick test or blood test. A positive allergy test result doesn't always mean you have an allergy. Ask your doctor what your results mean in your situation.

How is a peanut allergy treated?

Once your doctor confirms peanut allergy, they will prepare an allergy action plan. The action plan will be:

• red if you need an adrenaline autoinjector (brand names EpiPen or Anapen)
• green if you don't need an adrenaline autoinjector

Your action plan tells you what to do if you are exposed to peanuts.

There is no cure for peanut allergy.

Currently, the best treatment for a peanut allergy is to completely avoid exposure to peanuts.

Immunotherapy

In some people, it is possible to ease allergy symptoms by being exposed to tiny quantities of allergen. The amount of allergen is gradually increased over time. This is called ‘desensitisation therapy' or ‘allergen immunotherapy'.

This type of treatment is often used to treat other allergies (for example, pollen). It is not yet widely used in food allergy. Research shows promising results, especially for peanut allergy.

Desensitisation therapy should only happen with close supervision by a medical specialist because of the risk of anaphylaxis.

Living with a peanut allergy

If you are allergic to peanuts, you must avoid any exposure to them. This can be very challenging.

It's important to know which foods may contain peanuts so you can avoid them. Here are some other tips:

• Always carry your adrenaline autoinjector (EpiPen or Anapen), even if you don't expect to eat.
• Tell others about your allergy and what to do if you are exposed to peanuts.
• Be careful when kissing or hugging — peanut traces can stay on hands, lips, teeth, beards and moustaches.
• Carry a supply of safe food with you when travelling.
• Check that cosmetics you buy are free from peanut products.

Other possible sources of allergen can be:

• medicines
• alternative therapies
• pet food

Eating at home

When eating at home you should always read food labels — peanuts can easily be hidden. In Australia, common allergens must be listed on the food label.

Take care with knives and forks, kitchen surfaces, barbecue plates, and shared butter and margarine that might be contaminated.

Eating out

Take extra care when eating out. Peanuts are commonly used in:

• Asian and Indian food
• sauces, dressings or salads
• desserts

At restaurants, don't rely on menu descriptions when ordering foods and drinks. Tell them about your allergy and ask about ingredients and the chance of cross-contamination.

Allergy and Anaphylaxis Australia has developed a peanut allergen card and a chef card to bring with you when eating out. You can give it to the wait staff or chef when telling them about your allergy. It's also available in a variety of languages, if you are travelling.

Children with allergies

Children should take their own food to school and parties.

Children should never share or swap food with other children.

Children with a peanut allergy may need to eat separately from other children, but take care not to exclude them socially.

What are the complications of a peanut allergy?

If someone with a peanut allergy is exposed to peanuts, they may develop a serious allergic reaction (anaphylaxis), which may be life-threatening.

Can a peanut allergy be prevented?

Peanut allergy can't be completely prevented, but there are things you can do to reduce your child's chance of developing a peanut allergy:

• Introduce solid food between 4 and 6 months of age.
• Try to introduce common foods allergens (including peanuts) in an age-appropriate form (such as smooth peanut butter or paste) before 12 months of age. This advice also applies to children who may have a higher chance of developing food allergy, such as those with severe eczema or egg allergy, or those with a family member who has a food allergy.
• Breastfeed for at least 6 months, if you can.
• Eat a healthy, balanced diet during pregnancy and while breastfeeding. Avoiding peanuts during pregnancy or breastfeeding does not reduce your child's chance of allergy.
• If your child has eczema, make sure it is well-controlled.
• Do not smoke during pregnancy or around your young child.

Resources and support

• You can read more about peanut, tree nut and seed allergy on the Australian Society of Clinical Immunology and Allergy (ASCIA) website including tips to avoid tree nuts and peanuts.
• Allergy & Anaphylaxis Australia (A & AA) gives guidance and advice to Australians living with allergic disease. You can call them on 1300 728 000.
• Nip Allergies in the Bub has information for parents about introducing common allergy foods to children.

Other languages

Nip Allergies in the Bub has resources about introducing common allergy foods to babies in a variety of community languages.

Call the healthdirect helpline on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available 24 hours a day, 7 days a week.