Know what you're eating

The 14 mandatory allergens

UK food law requires businesses to declare 14 allergens whenever they are used as ingredients. Here is everything you need to know about each one.

Jump to:GlutenCrustaceansEggsFishPeanutsSoyaDairyNutsCeleryMustardSesameSulphitesLupinMolluscs
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Allergen 01

Gluten

What is it

Gluten is a protein found in wheat, rye, barley and oats. It gives bread and pastry its elastic texture.

Coeliac disease affects around 1 in 100 people in the UK. 64% remain undiagnosed.

Commonly found in

  • Bread, pasta, cereals
  • Cakes, biscuits, pastries
  • Beer and ales
  • Sauces and gravies (thickened with flour)
  • Some ready meals

Possible symptoms

  • Digestive discomfort, bloating and diarrhoea
  • Fatigue and brain fog
  • In coeliac disease: serious intestinal damage
  • Skin rash (dermatitis herpetiformis)
  • Anaemia in severe cases
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Allergen 02

Crustaceans

What is it

Crustaceans include shellfish such as prawns, crabs, lobster and crayfish. One of the more common causes of severe allergic reaction.

Crustacean allergy is often lifelong and can cause anaphylaxis โ€” a life-threatening emergency.

Commonly found in

  • Prawns and shrimp
  • Crab and lobster
  • Crayfish
  • Prawn crackers
  • Some seafood sauces and pastes

Possible symptoms

  • Hives, itching or eczema
  • Swelling of lips, face or throat
  • Nausea, vomiting or diarrhoea
  • Anaphylaxis in severe cases
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Allergen 03

Eggs

What is it

Egg allergy is one of the most common food allergies, particularly in children. Both egg white and egg yolk can trigger reactions.

Many children outgrow egg allergy by their teenage years, though it can persist into adulthood.

Commonly found in

  • Cakes, biscuits and pastries
  • Mayonnaise and salad dressings
  • Pasta (fresh or egg pasta)
  • Quiche and omelettes
  • Some breaded or battered foods

Possible symptoms

  • Skin reactions including hives
  • Runny nose and sneezing
  • Stomach cramps and nausea
  • Vomiting and diarrhoea
  • Anaphylaxis in rare cases
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Allergen 04

Fish

What is it

Fish allergy refers to finned fish such as cod, haddock, salmon, tuna and bass. It is separate from shellfish (crustacean and mollusc) allergies.

Fish allergy is often lifelong. People allergic to one type of fish may react to others.

Commonly found in

  • Fresh and frozen fish
  • Fish fingers and fish cakes
  • Fish sauce and Worcestershire sauce
  • Some Caesar dressings
  • Certain Asian dishes and sauces

Possible symptoms

  • Hives or skin rash
  • Swelling around the mouth
  • Digestive symptoms
  • Difficulty breathing
  • Anaphylaxis in severe cases
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Allergen 05

Peanuts

What is it

Peanuts are legumes, not true nuts. Peanut allergy is one of the most common and serious food allergies, often causing severe reactions.

Peanut allergy affects around 2% of children in the UK. Even trace amounts can trigger severe reactions.

Commonly found in

  • Peanut butter
  • Satay sauces
  • Some curries and Asian dishes
  • Cereal bars and snacks
  • Some baked goods and chocolates

Possible symptoms

  • Tingling or itching in the mouth
  • Hives, redness or swelling
  • Tightening of the throat
  • Shortness of breath
  • Anaphylaxis โ€” can be fatal without treatment
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Allergen 06

Soya

What is it

Soya (soy) comes from soybeans. It is widely used as a protein source and food additive, making it easy to accidentally consume.

Soya is extremely common in processed foods. Always check labels carefully.

Commonly found in

  • Tofu and tempeh
  • Edamame beans
  • Soy sauce and miso
  • Many meat alternatives
  • Some breads, cereals and ready meals

Possible symptoms

  • Tingling in the mouth
  • Hives or itching
  • Swelling of lips or tongue
  • Stomach pain and nausea
  • Anaphylaxis in rare cases
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Allergen 07

Dairy

What is it

Dairy allergy is a reaction to proteins in cow's milk (casein and whey). It is different from lactose intolerance, which is a digestive issue rather than an immune response.

Dairy allergy is most common in infants but many outgrow it. Lactose intolerance is a separate, non-allergic condition.

Commonly found in

  • Milk, butter, cream and cheese
  • Yoghurt and ice cream
  • Chocolate and caramel
  • Many baked goods
  • Sauces, soups and ready meals

Possible symptoms

  • Hives or skin rash
  • Vomiting shortly after consumption
  • Diarrhoea and stomach cramps
  • Wheezing or coughing
  • Anaphylaxis in severe cases
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Allergen 08

Nuts

What is it

Tree nut allergy covers almonds, hazelnuts, walnuts, cashews, pistachios, Brazil nuts, pecans, macadamia nuts and others. It is separate from peanut allergy.

Tree nut allergy is usually lifelong. Being allergic to one tree nut increases the likelihood of reacting to others.

Commonly found in

  • Nut butters and spreads
  • Marzipan and praline
  • Some curries and Asian dishes
  • Pesto (pine nuts)
  • Cereals, granola and energy bars

Possible symptoms

  • Itching or swelling of the mouth and throat
  • Hives and skin reactions
  • Nausea and vomiting
  • Difficulty breathing
  • Anaphylaxis
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Allergen 09

Celery

What is it

Celery allergy covers all parts of the plant including the stalk, leaves, seeds and root (celeriac). It can cause reactions even in small amounts.

Celery is often hidden in stocks, spice blends and processed foods. Celeriac (celery root) is also a trigger.

Commonly found in

  • Celery stalks and celeriac
  • Celery salt and seeds
  • Some soups and stocks
  • Certain spice mixes and seasonings
  • Some ready meals and sauces

Possible symptoms

  • Tingling or swelling of the mouth
  • Skin reactions
  • Digestive upset
  • Runny nose
  • Anaphylaxis in severe cases
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Allergen 10

Mustard

What is it

Mustard allergy covers mustard seeds, powder, paste and oil. It is a relatively common allergy in the UK and Europe.

Mustard is often found hidden in spice blends and processed foods โ€” not just on the condiment shelf.

Commonly found in

  • Mustard condiments and sauces
  • Salad dressings and marinades
  • Some curries and spice blends
  • Certain breads and crackers
  • Processed meats

Possible symptoms

  • Oral allergy syndrome (tingling mouth)
  • Hives and skin reactions
  • Digestive discomfort
  • Runny nose and watery eyes
  • Anaphylaxis in severe cases
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Allergen 11

Sesame

What is it

Sesame allergy has been increasing in prevalence. It covers sesame seeds, sesame oil and tahini (sesame paste).

Sesame is increasingly common in UK diets. It was added to the mandatory allergen list due to rising allergy rates.

Commonly found in

  • Sesame seeds on bread and buns
  • Tahini and hummus
  • Sesame oil in Asian cooking
  • Some salad dressings
  • Certain cereal bars and snacks

Possible symptoms

  • Mouth tingling and swelling
  • Hives or eczema flare-up
  • Stomach cramps and nausea
  • Breathing difficulties
  • Anaphylaxis
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Allergen 12

Sulphites

What is it

Sulphur dioxide and sulphites are preservatives used to extend shelf life and maintain colour. They must be declared when present at more than 10mg/kg or 10mg/litre.

People with asthma are particularly sensitive to sulphites. They are one of the few allergens measured by concentration threshold.

Commonly found in

  • Wine and beer
  • Dried fruits (apricots, raisins)
  • Some meat products
  • Pickled foods and vinegar
  • Fruit juices and cordials

Possible symptoms

  • Breathing difficulties (especially in asthmatics)
  • Skin flushing
  • Headaches
  • Stomach upset
  • Anaphylaxis in rare cases
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Allergen 13

Lupin

What is it

Lupin is a flowering plant whose seeds are used as flour in some bread, pastries and pasta products. It is related to peanuts and may cross-react.

Lupin is particularly common in continental European foods. People with peanut allergy may also react to lupin.

Commonly found in

  • Lupin flour in bread and pastries
  • Some pasta and pizza bases
  • Certain gluten-free products
  • Some meat alternatives
  • Continental bakery products

Possible symptoms

  • Skin reactions and hives
  • Swelling of lips and throat
  • Breathing difficulties
  • Digestive upset
  • Anaphylaxis โ€” particularly in those with peanut allergy
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Allergen 14

Molluscs

What is it

Molluscs include squid, mussels, oysters, scallops, clams and octopus. Like crustaceans, mollusc allergy can be severe.

Mollusc allergy is distinct from crustacean allergy. Being allergic to one does not necessarily mean you are allergic to the other.

Commonly found in

  • Mussels, oysters and clams
  • Squid and octopus
  • Scallops
  • Some seafood sauces and pastes
  • Certain Asian dishes

Possible symptoms

  • Tingling or itching in the mouth
  • Hives and skin swelling
  • Stomach cramps and vomiting
  • Breathing difficulties
  • Anaphylaxis

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