An allergy, sometimes confused with an intolerance, is an overreaction by the body’s immune system to a normally harmless substance. Substances that can trigger an allergic reaction are called allergens.  Allergens may be in medication, in the environment (eg. pollens, grasses, moulds, dogs and cats), or sometimes proteins in the foods we eat. Individuals can have mild or severe allergies.

In Australia allergies are very common. Around one in three people will develop allergies at some time during their life. The most common allergic conditions are food allergies, eczema, asthma and hay fever. Food allergy occurs in around ten percent of children¹ and two percent of adults.

Having a food allergy means that when you eat a food containing that protein (or allergen), the immune system releases massive amounts of chemicals, triggering symptoms that can affect a person’s breathing, stomach and gut, skin and/ or heart and blood pressure.

For someone with a severe food allergy, exposure to the food allergen can cause a life-threatening reaction called anaphylaxis.  Anaphylaxis affects the whole body, often within minutes of eating the food.  Symptoms may include the rapid spreading of hives, swelling of the face, lips and eyes, vomiting, wheezing, coughing and loss of consciousness.  The most serious symptoms are breathing difficulties and/or a sudden drop in blood pressure which can be life-threatening.

¹Osborne et al. Prevalence of challenge-proven IgE-mediated food allergy
using population-based sampling and predetermined
challenge criteria in infants. J Allergy Clin Immunolol 2011; 127: 668-676