What causes an allergy?

‘Allergens,’ the things that people are allergic to, are usually everyday substances that other people can tolerate.

Common allergens include animal hair, pollen, mould, dust mites, insect stings, peanuts and other nuts, crustaceans and fish, and some types of medications.

You maybe allergic to a substance if the allergens touches your skin, if you breathe it in, or if you ingest it and your immune system reacts.

These allergens come into contact with the antibodies, which release substances like histamine, that cause inflammation and swelling.

Allergens inhaled may affect your nose, eyes, sinuses and throat. They may become swollen, inflamed or itchy, with extra mucus produced in the nose and fluid in the eyes.  

Inhaling allergens may affect your lungs and / or trigger asthma.

Allergens in foods or liquids that you ingest may affect your stomach and bowel. Symptoms of an allergic reaction triggered by food or drink can include abdominal upsets like nausea, vomiting, or abdominal pain.

Eczema and Hives may be caused by allergens that have been ingested or have come into contact with your skin.

Australia and New Zealand have among the highest prevalence of allergic disorders in the developed world.