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Food allergy

Symptoms of a food allergy include a raised, itchy red rash, swelling of the face, eyes, lips, tongue, and a shortness of breath.

The symptoms of a food allergy almost always develop a few seconds or minutes after eating the food.

Some people may develop a severe allergic reaction (anaphylaxis), which can be life-threatening.

The most common type of allergic reaction to food is known as an IgE-mediated food allergy.

Symptoms include:

  • tingling or itching in the mouth
  • a raised, itchy red rash (urticaria) – in some cases, the skin can turn red and itchy, but without a raised rash
  • swelling of the face, mouth (angioedema) or other areas of the body
  • difficulty swallowing
  • wheezing or shortness of breath
  • feeling dizzy and lightheaded
  • feeling sick (nausea) or vomiting
  • abdominal pain or diarrhoea
  • hay fever-like symptoms, such as sneezing or itchy eyes (allergic conjunctivitis)


The symptoms of a severe allergic reaction (anaphylaxis) can be sudden and get worse very quickly.

Initial symptoms of anaphylaxis are often the same as those listed above and can lead to:

  • increased breathing difficulties  such as wheezing and a cough
  • a sudden and intense feeling of anxiety and fear
  • a rapid heartbeat (tachycardia)
  • a sharp and sudden drop in your blood pressure, which can make you feel light-headed and confused
  • unconsciousness

Anaphylaxis is a medical emergency. Without quick treatment, it can be life-threatening. If you think you or someone you know is experiencing anaphylaxis, dial 999 and ask for an ambulance as soon as possible.

Non-IgE-mediated food allergy

Another type of allergic reaction is a non-IgE-mediated food allergy. The symptoms of this type of allergy can take much longer to develop – sometimes up to several days.

Some symptoms of a non IgE-mediated food allergy may be what you would expect to see in an allergic reaction, such as:

  • redness and itchiness of the skin  although not a raised, itchy red rash (urticaria)
  • the skin becomes itchy, red, dry and cracked (atopic eczema)

Other symptoms can be much less obvious and are sometimes thought of as being caused by something other than an allergy. They include:

  • heartburn and indigestion that is caused by stomach acid leaking up out of the stomach (gastro-oesophageal reflux disease)
  • stools (poo) becoming much more frequent or loose (though not necessarily diarrhoea)
  • blood and mucus in the stools
  • in babies: excessive and inconsolable crying, even though the baby is well-fed and doesn't need a nappy change (colic)
  • constipation 
  • redness around the anus, rectum and genitals
  • unusually pale skin
  • failure to grow at the expected rate

Mixed reaction

Some children can have a mixed reaction where they experience both "IgE" symptoms, such as swelling, and "non-IgE" symptoms, such as constipation.

This often happens to children who have a milk allergy.

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Food allergy

There is no cure for food allergies, although many children will grow out of certain ones, such as allergies to milk and eggs. The most effective way you can prevent symptoms is to remove the offending food (known as an allergen) from their diet.

The advice here is primarily written for parents of a child with a food allergy. However, most of it is also relevant if you are an adult with a food allergy.

Your child’s diet

There is no cure for food allergies, although many children will grow out of certain ones, such as allergies to milk and eggs. The most effective way you can prevent symptoms is to remove the offending food (known as an allergen) from their diet.

However, it's important to check with your GP or the doctor in charge of your child’s care first before eliminating certain foods.

Removing eggs or peanuts from a child's diet is not going to have much of an impact on their nutrition. Both types of these are a good source of protein, but can be replaced by other alternative sources.

A milk allergy can have more of an impact as milk is a good source of calcium, but there are many other ways you can include calcium in your child’s diet, including green leafy vegetables.

Many foods and drinks are fortified with extra calcium.

If you are concerned that your child’s allergy is affecting their growth and development, see your GP.

Reading labels

It's very important to check the label of any pre-packed food or drinks your child has, in case it contains ingredients they are allergic to.

Under EU law, any pre-packed food or drink sold in the UK must clearly state on the label if it contains the following ingredients:

  • celery
  • cereals that contain gluten (including wheat, rye, barley and oats)
  • crustaceans (including prawns, crabs and lobsters)
  • eggs
  • fish
  • lupin (lupins are common garden plants, and the seeds from some varieties are sometimes used to make flour)
  • milk
  • molluscs (including mussels and oysters)
  • mustard
  • tree nuts  such as almonds, hazelnuts, walnuts, brazil nuts, cashews, pecans, pistachios and macadamia nuts
  • peanuts
  • sesame seeds
  • soybeans
  • sulphur dioxide and sulphites (preservatives that are used in some foods and drinks) at levels above 10mg per kg or per litre

Some food manufacturers also choose to put allergy advice warning labels (for example, "contains nuts") on their pre-packed foods if they contain an ingredient that is known to commonly cause an allergic reaction, such as peanuts, eggs or milk.

However, these are not compulsory. If there is no allergy advice box or "contains" statement on a product, it could still have any of the 14 specified allergens in it.

Look out for "may contain" labels, such as "may contain traces of peanut". Manufacturers sometimes put this label on their products to warn consumers that they may have become contaminated with another food product when being made.

Read more detailed information about allergen labelling on the Food Standards Agency website.

Some non-food products contain allergy-causing food:

  • Some soaps and shampoos contain soy, egg and tree nut oil.
  • Some pet foods contain milk and peanuts.
  • Some glues and adhesive labels used on envelopes and stamps contain traces of wheat.

Again, read the labels of any non-food products that your child may come into close physical contact with.

Unpackaged food

Currently, unpackaged food doesn't need to be labelled in the same way as packaged food. This can make it more difficult to know what ingredients are in a particular dish.

Examples of unpackaged food include food sold from:

  • bakeries (including in-store bakeries in supermarkets)
  • delis
  • salad bars
  • "ready-to-eat" sandwich shops
  • takeaways
  • restaurants

If you or your child have a severe food allergy, you need to be careful when you eat out.

The following advice should help:

  • Let the staff know. When booking a table at a restaurant, make sure the staff know about your child’s allergy. Ask for a firm guarantee that the food you or your child is allergic to won't be in any of the dishes served. The Food Standards Agency (FSA) offers chef cards that provide information about your child’s food allergy, which you can give to restaurant staff. As well as informing the chef and kitchen staff involved in cooking your food, let waiters and waitresses know so they understand the importance of avoiding cross-contamination when serving you.
  • Read the menu carefully and check for "hidden ingredients". Some food types contain other foods that can trigger allergies, which restaurant staff may have overlooked. Some desserts contain nuts (such as a cheesecake base) and some sauces contain wheat and peanuts.
  • Prepare for the worst. It's a good idea to prepare for any eventuality. Always take your child’s anti-allergy medication with you when eating out, particularly if they have been given an auto-injector of adrenalin (read more about treating food allergies with a auto-injector).
  • In older children, you can use what is known as a "taste-test". Before your child begins to eat, ask them to take a tiny portion of the food and rub it against their lips to see if they experience a tingling or burning sensation. If they do, it suggests that the food will cause them to have an allergic reaction. However, the "taste-test" doesn't work for all foods, so it shouldn't be used as a substitute for the above advice.

The FSA has produced a factsheet about buying food and eating out with a food allergy (PDF, 220kb).

Further advice

Here is some more advice for parents: 

  • Notify your child's school about their allergy. Depending on how severe your child’s allergy is, it may be necessary to give the staff at their school an emergency action plan in case of accidental exposure. Arrange for the school nurse or another staff member to hold a supply of adrenalin. Food allergy bracelets are also available, which explain how other people can help your child in an emergency.
  • Let other parents know. Young children may easily forget about their food allergy and accept food that they shouldn't have when visiting other children. Telling the parents of your child’s friends about their allergy should help prevent this.
  • Educate your child. Once your child is old enough to understand their allergy, it's important to give them clear, simple instructions about what foods to avoid and what they should do if they accidentally eat them. 

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Food allergy

Once you have been diagnosed as having a food allergy, you will receive advice about antihistamines, adrenaline and using an auto-injector.

There are two main types of medication that can be used to relieve the symptoms of an allergic reaction to foods:

  • antihistamines, which can be used to treat mild to moderate allergic reaction
  • adrenaline, which can be used to treat severe allergic reactions (anaphylaxis)


Antihistamines work by blocking the effects of histamine, which is responsible for many of the symptoms of an allergic reaction.

Many antihistamines are available from your pharmacist without prescription  stock up in case of an emergency. Non-drowsy antihistamines are preferred.

Some antihistamines, such as alimemazine and promethazine, aren't suitable for children under two years old. If you have a younger child with a food allergy, ask your GP about what types of antihistamines may be suitable.

Avoid drinking alcohol after taking an antihistamine as this can make you feel drowsy.


Adrenaline works by narrowing the blood vessels to counteract the effects of low blood pressure, and by opening up the airways to help ease breathing difficulties.

If you or your child is at risk of anaphylaxis or has had a previous episode of anaphylaxis, you will be given an auto-injector of adrenaline to use in case of emergencies.

Carefully read the manufacturer’s instructions that come with the auto-injector and when your child is old enough, train them how to use it (see below).

Using an auto-injector

If you suspect that somebody is experiencing the symptoms of anaphylaxis, call 999 and ask for an ambulance. Tell the operator that you think the person has anaphylaxis.

Older children and adults will probably have been trained to inject themselves. You may need to inject younger children, or older children and adults who are too sick to inject themselves.

There are three types of auto-injectors:

All three work in much the same way. If anaphylaxis is suspected, you should remove the safety cap from the injector, place it against your outer thigh (holding it at a right angle) and hold down the firing button at the end of the injector. The injections can be given through clothing.

This will send a needle into your thigh and deliver a dose of adrenaline. You need to hold down the button for 10 seconds.

If the person is unconscious, check their airways are open and clear, and check their breathing. Then put them in the recovery position (see below). Putting someone who is unconscious in the recovery position ensures they do not choke on their vomit.

Place the person on their side, making sure they are supported by one leg and one arm. Open the airway by tilting the head and lifting the chin.

If the person's breathing or heart stops, cardiopulmonary resuscitation (CPR) should be performed.

Owning an auto-injector

As a precaution, the following advice should be taken: 

  • Carry the auto-injector at all times or encourage your child to do so if they are old enough. You may be recommended to carry multiple injectors  check with your GP or the doctor in charge of your care. You may also be given an emergency card or bracelet with full details of your child’s allergy and contact details of their doctor, to alert others. They should wear this at all times.
  • Extreme temperatures can make adrenaline less effective. Do not leave an auto-injector in places such as your fridge or the glove compartment of your car.
  • Check the expiry date regularly. EpiPen and Jext have a shelf life of 18 months after the date of manufacture, and Anapen has a shelf life of two years. An out-of-date injector will only offer limited protection.
  • The manufacturers offer a reminder service, where you can be contacted near the date of expiry. Check the information leaflet that comes with the medication for more information.
  • If your child has an auto-injector, they will need to change over to an adult dose once they reach a weight of 30 kilos (4.7 stone). Depending on the shape and size of your child’s body, this could be anywhere between the ages of 5 and 11 years old.
  • Do not delay injecting if you think you or your child may be experiencing the start of anaphylaxis, even if the initial symptoms are mild. It's better to use adrenaline early and find out it was a false alarm than delay treatment until you are sure your child is experiencing severe anaphylaxis. 
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Food allergy

Sheila Coovrey from Bedfordshire, has lived with a fish allergy for most of her life.

Sheila Coovrey, from Bedfordshire, has lived with a fish allergy for most of her life.

“Every time I had fish as a baby, I vomited. But at that time, allergies were not widely recognised so my mum carried on giving it to me. If I was ever given fresh fish, I always vomited, had bad pains in my stomach and sometimes fainted."

“I can eat fish that is tinned or smoked, but any other form of fish makes me very ill. Throughout my life, I have simply avoided eating fish. There is no other treatment. The best method is to avoid it."

“I have to be very careful in restaurants. I always have to explain my allergy when I go to a restaurant, and I have to make sure my food is not cooked with fish. Food labels now state allergens more clearly, so I always check labels too."

“The worst experience with my allergy was when I ate paella in a restaurant. I didn’t realise there was fish in it, and I vomited and passed out in the middle of the restaurant." 

“My advice to anyone with a food allergy is to see your doctor and take any tests that are offered, so you know exactly what you're allergic to. Always check labels carefully and be vigilant in restaurants, at weddings and any other social functions.”

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