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 common, otherwise harmless, substances in food. A very low level of an allergenic substance may cause a potentially fatal allergic reaction in susceptible individuals. A local survey revealed that about 1 in 20 children in Hong Kong reported having a food allergy. Therefore, it is necessary for all school catering staff to be fully educated about what foods contain allergens, and which foods are suitable for specific dietary needs.

Common food allergens include:

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

Symptoms of food allergies usually develop within several minutes to two hours after consuming the offending food.

Common food allergy symptoms include rash, swollen face or lips, shortness of breath and itchy skin.

rash, swollen face or lips, shortness of breath and itchy skin.

In most cases, allergic reactions to food are uncomfortable but not particularly dangerous. However, food allergies can cause a potentially fatal reaction known as anaphylactic shock in severe instances. This can present severe symptoms including constriction of the airways, difficulty breathing, severe drop in blood pressure and loss of consciousness. Anaphylactic shock requires immediate emergency care.

Advice for schools and childcare facilities

To minimise the risks of food allergy in children, schools and childcare facilities are advised to:

Relevant information