In a nutshell: Some people may have food allergies to certain foods, and food allergies can range from mild to severe and can be fatal. If you experience food allergy symptoms after eating, seek medical attention immediately. Check food labels for allergen information to avoid eating foods that contain allergens.

What is food allergy?

Food allergy is a reaction of the body's immune system to some substances in food. A very low level of an allergenic substance may cause an allergic reaction in susceptible populations. A local survey revealed that about 1 out of 20 children in Hong Kong was reported to have food allergies.

Common allergens are:

Common allergens


Some typical examples of food item in which allergens may be found

Cereals that contain gluten (e.g. wheat, rye, barley and oats)
  • In foods containing flour, such as bread, pasta, cakes, pastry, meat products, sauces, soups, batter, stock cubes, breadcrumbs, foods dusted with flour, vegetarian products (e.g. plant-based milk)
Crustaceans (e.g. prawns, crabs and lobsters)
  • In shrimp paste
  • In cakes, mousses, sauces, pasta, quiche, some meat products, mayonnaise, foods brushed with egg
  • In some salad dressings, pizzas, relishes, fish sauce, other sauces (e.g. soy and Worcestershire sauces)
  • In yoghurt, cream, cheese, butter, milk powders, foods glazed with milk
Molluscs (e.g. mussels and oysters)
  • In oyster sauce
Tree nuts (e.g. almonds, cashews, hazelnuts, pecans and walnuts)
  • In sauces, desserts, crackers, bread, ice cream, marzipan, ground almonds, nut oils, vegetarian products (e.g. plant-based milk)
  • In sauces and spread (e.g. peanut butter), cakes, desserts, groundnut oil, peanut flour
  • In beancurd (tofu), green soybeans (edamame), fermented beans (douchi), tempeh, soya flour, textured soya protein, certain ice-cream, soy sauces, desserts, meat products, vegetarian products (e.g. plant-based milk and meat)
Sulphur dioxide and sulphites
  • In meat products, fruit juice drinks, dried fruit and vegetables, wine, beer

Symptoms of food allergy include swollen face, tongue or lips, shortness of breath and itchy skin. Anaphylactic shock, an acute, severe and potentially life-threatening allergic reaction may develop in severe cases.

Seek medical advice at once if the following symptoms develop after meal:

Seek medical advice at once if the following symptoms develop after meal

How to avoid food with allergens?

Relevant Information