What is a Food Allergy?

Most food allergies affect children who are under three. Some of the most common allergies to affect young children include allergies to peanuts and cows’ milk; luckily, research suggests that the majority of children will grow out of their cows’ milk allergy by the age of five.

A nut allergy is more likely to continue into adult life with only around one fifth of children growing out of a peanut allergy by the time they reach the age of 10.

Occasionally, food allergies can begin during adulthood and it is not always clear why this happens.

What are food allergies?

Sometimes, when a person consumes a specific food or drink their immune system reacts in an unusual way – this is known as a food allergy. When someone experiences the symptoms of a food allergy this is referred to as an allergic reaction.

An allergic reaction occurs if the immune system incorrectly identifies the proteins in certain foods as a threat and releases chemicals, including histamine. The chemical histamine is responsible for many of the common symptoms of an allergic reaction such as swelling or itching.

The symptoms that occur when a person consumes something that they are allergic to range from mild to severe. In extreme circumstances a person can experience an allergic reaction called anaphylaxis that can prove fatal. During anaphylaxis, the immune system overreacts to the allergens, releasing large amounts of histamine plus other chemicals into the bloodstream.

As food allergies can have serious implications, businesses that are producing and handling consumables need to take reasonable precautions to make sure that they correctly label any allergens present.

What are the types of food allergies?

Some of the most common foods that cause allergic reactions include:

• Milk.
• Eggs.
• Peanuts.
• Shellfish.

People can be allergic to a range of different ingredients and foods; however, there are 14 allergens that the law requires food businesses must declare on their menus or food labels in the UK. It is important that businesses communicate clearly to their customers if any of these allergens are, or may be, present in their items.

The 14 allergens are:

• Celery.
• Cereals that contain gluten (including wheat, barley and oats).
• Crustaceans (including prawns and crabs).
• Eggs.
• Fish.
• Lupin.
• Milk.
• Molluscs (including mussels and oysters).
• Mustard.
• Peanuts.
• Sesame.
• Soy.
• Sulphur dioxide/sulphites (if they are at a higher concentration that 10 parts per million).
• Tree nuts (including hazelnuts, pistachios, cashews and walnuts).

These allergens apply to not only the finished product but also any ingredients, manufacturing or processing methods used.

What are the signs and symptoms of food allergies?

It is unclear why some people develop allergies to different foods; however, there is a correlation between children who have eczema in infancy and food allergies. In addition to eczema, many people with food allergies also suffer from types of allergies and conditions such as hay fever or asthma.

Symptoms of a food allergy differ between people and can range from uncomfortable and annoying to life threatening.

The most common symptoms of a food allergy are:

• An itchy, red skin rash.
• Itching and tingling inside the mouth, throat or ears.
• Nausea/vomiting.
• Facial swelling (around the eyes, lips, tongue and roof of the mouth).

The symptoms of a food allergy will usually show up quickly after the allergen is consumed.

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

Reactions within the gut:

• Nausea or vomiting.
• Abdominal pain/discomfort or diarrhoea.

Reactions of the skin:

• Red and itchy skin, raised rash (hives).
• Itching and tingling in the mouth.
• Itchy eyes.
• Swelling around the face/ears.

Reactions within the respiratory system:

• Wheezing.
• Shortness of breath.
• Trouble swallowing.
• Sneezing.

The symptoms of a severe allergic reaction known as anaphylaxis can appear suddenly and progress quickly. Anaphylaxis is an emergency and can be very scary to witness and even scarier to experience. If someone is experiencing symptoms of anaphylaxis it is vital that someone calls 999 immediately.

The symptoms of anaphylaxis might look similar from the outside to someone having a severe asthma attack and they include:

• Difficulty breathing.
• Tightness in the chest.
• Problems with swallowing or speaking.
• Dizziness.
• Swollen tongue or throat.
• Collapse.

A less common reaction is known as a Non-IgE-mediated food allergy. With this type of reaction, the symptoms take some time to show (sometimes several hours).

People can also sometimes experience a combination of the two types of allergic reactions.

How are food allergies different from a food intolerance?

A food allergy and a food intolerance are not the same thing.

The symptoms of a food intolerance usually include:

• Bloating.
• Stomach pain/cramps.
• An upset stomach/diarrhoea.

Some key differences between a food allergy and a food intolerance are:

• The symptoms of a food intolerance do not show immediately and may take several hours to appear.
• You may only need to eat a small amount of a food you are allergic to in order to trigger an allergy; intolerances require a larger amount of the trigger food to be consumed.
• A food intolerance is not life threatening, whereas an allergy can be.

How are food allergies diagnosed?

You need to identify the allergen that is causing symptoms in order to be able to manage it. In many cases this may be obvious as symptoms usually come on quite soon after consuming the problem allergen.

If you are concerned about an allergy or you think your child might have one, you can make an appointment with your doctor. They will ask questions about the symptoms, how soon they came on after consuming certain food/drink and how serious they are. They will also need to ask some general health and lifestyle questions.

In cases where a child is being diagnosed, your doctor will also want to know:

• Any family history of allergies.
• Was the child bottle or breast fed.
• Do they have other allergies (such as eczema).

If your GP thinks it is necessary, they might refer you to the hospital for some allergy testing. This may include:

• Skin prick testing – this involves droplets containing allergens being put onto the skin. The skin is then pricked which allows the allergen to enter your body enough to come into contact with your immune system. A positive reaction might include itching, swelling or redness.
• Blood test – a blood allergy test measures the amount of IgE allergy antibodies in the bloodstream in relation to specific allergens.

For cases where the symptoms are less severe, your doctor may suggest a food elimination diet. This is where the food that may have caused an allergic reaction is avoided for a period of several weeks then introduced again. If the symptoms go away when the food has been eliminated but then come back when it is reintroduced that suggests an allergy.

You should talk with a doctor or qualified dietician about how to approach a food elimination diet safely.

You can also buy allergy testing kits online or from shops; however, the reliability of these tests is disputed by experts.

It is possible to be allergic to a combination of things, so your tests might show sensitivity to one, or several, of the known allergens.

How are food allergies treated?

To avoid further allergic reactions, once the allergen in question has been identified you should avoid consuming it again as far as possible. Sometimes this may mean making significant changes to your diet or getting used to checking the packaging and ingredient list in the supermarket before you purchase items. The best way to avoid having another allergic reaction, especially if you have had a severe one, is to avoid the trigger.

If you need to make major changes to your diet, such as completely eliminating dairy, you should speak to your GP first. They may suggest that you start taking a multivitamin or calcium tablet as you may start to lack nutrients if you radically overhaul your eating habits. You may also want to book a session with a dietician who has a better understanding of allergies and can advise you on how to navigate life with a food allergy more easily.

Aside from making dietary changes, there are two main types of medication that are used to manage food allergies:

• Antihistamines.
• Adrenaline.

Antihistamines are widely available over the counter in pharmacies, although some can also be obtained on prescription. Antihistamines are medicines that are used to effectively treat a number of allergy related conditions including hives, hay fever, reactions to mosquito or other insect bites/ stings and some of the symptoms related to food allergies.

They work by blocking histamine – the substance released into the blood when the body identifies a benign substance as harmful. Histamine causes swelling and the expansion of blood vessels which is responsible for many of the symptoms of a food allergy such as itchy skin or swollen eyes.

Taking antihistamine before you come into contact with an allergen can help to stop allergic symptoms from occurring. You can also take them after consuming an allergen to try to reduce the severity of the symptoms you are experiencing.

Adrenaline helps to relieve low blood pressure by narrowing blood vessels. It also helps to open up airways and relieve breathing difficulties.

Many people who have a severe allergy that can cause anaphylaxis need to carry an epinephrine auto-injector, also commonly known as an EpiPen (a type of auto-injector), with them at all times. This is a form of hypodermic device that contains adrenaline. They are used to quickly and effectively deliver medicine to treat allergy related emergencies.

If a person is experiencing anaphylaxis, you can use an auto-injector to administer live-saving adrenaline to them as follows:

1. Remove the safety cap from the injector
2. Place it firmly against the thigh at a right angle
3. A ‘click’ sound means that adrenaline release has been activated
4. Keep it in place for 10 seconds

An auto-injector can be used in the thigh area through clothing, providing that the needle is able to penetrate the skin.

A person experiencing anaphylaxis may require further first aid procedures after receiving their adrenaline shot such as being put in the recovery position or being given CPR. Providing you know how to do this safely you can do this whilst waiting for an ambulance to arrive.

How to manage food allergies

Research into allergies is ongoing and has made progress in recent decades, leading to the manufacture of many products labelled ‘free from’ which can be substituted for common food items that contain allergic triggers. This includes items such as:

• Bread and other baked goods that are free from gluten.
• Milk and cheese that is free from lactose.
• Cakes and baked sweet treats that are free from eggs.
• Dairy free chocolate.

Food law states that customers must be notified of the 14 allergens on prepacked foods, as well as in restaurants and on buffets. On packaging you will note that allergens are in bold to make them easier to identify.

If you have an allergy, you should pay careful attention to food labels, including ingredients and warnings such as ‘may contain traces of nuts’. This means that at some point the item may have come into contact with an allergen, although it does not specifically contain the allergen as an ingredient. The most common cause for this would be if cross-contamination may have occurred at some point.

You might assume that vegan food is allergen free; however, just because the item is free from eggs and dairy does not necessarily mean the factory where it was produced was. If you or your child has a severe allergy, always check the label or ask for advice rather than making assumptions.

You should also make any relevant people or organisations aware of allergies, such as your server if you go out to eat at a restaurant. If you have a child with an allergy you will need to make sure that other people who may care for them are aware of it, such as:

• Nursery.
• Childminder.
• School.
• Any clubs that they attend.
• Other parents (such as if they attend a party or playdate).

You should also make sure that they know how to use medication if your child were to have an allergic reaction (such as an EpiPen) and that you provide a supply of in-date medication and instructions for use.

If you share a living space with someone who has a severe food allergy you should be careful to avoid cross-contamination, such as using the same cutlery or cooking utensils without washing thoroughly in between, putting a knife in the butter that has been in peanut butter etc. Depending on the allergen in question and the possible reaction, it may be best to avoid having the allergen in the house at all.

According to the Food Standards Agency (FSA) an estimated 2 million people are living with a food allergy in the UK. It is encouraging to know that deaths relating to food allergies are rare and are also decreasing. This is due to improved food safety practices, clearer laws about the labelling of ingredients and a better understanding of how to deal with both allergens and allergic reactions.

Living with a food allergy, or having a child with one, can be disruptive and can add an extra level of stress to everyday life. Being allergy-aware requires you to be constantly checking what is in the food you are buying and consuming. The good news is that an improved understanding of allergies within society and an ever-expanding range of alternative and allergen-free products is making this easier.