What Causes Allergies?

A food allergy is an abnormal response by the immune system to a substance in food, usually protein. The food substance or protein causing the adverse reaction is called the allergen.

The body reacts to the allergen as if it were a foreign body. A reaction occurs within minutes or up to a few hours after the substance is eaten, and may lead to a range of different symptoms from mild to life threatening. Even tiny traces of the allergen will cause reactions and several parts of the body can become involved at the same time.

Common allergic reactions or symptoms include:

• Diarrhoea and vomiting
• Eczema, hives, reddening or flushing of the skin
• Swelling around the mouth, eyes and face
• Wheezing, difficulty breathing, stuffy nose, hay fever symptoms
• Anaphylaxis - a potentially life-threatening reaction involving the whole body.

People with a family history of allergies are more likely to develop food and other allergies. The chances of your child developing an allergy will depend on your family history and other environmental factors.

Most common food allergens are milk, eggs, nuts (especially peanuts), soy, wheat and fish.

If you suspect that your infant or child has a food allergy, it is important to have the allergy correctly diagnosed by a medical specialist such as a paediatrician or an immunologist.