Introduction to Allergies
Allergy is the term used to describe an adverse (bad) reaction by the body to a particular substance. Most things that cause allergies are not obviously harmful, and have no affect on people who are not allergic.
Allergies are very common and affect around one in four people in Ireland.
Any substance that triggers an allergic reaction is called an allergen. There are many different types of allergens. Three of the most common allergens are pollen, dust mites and nuts.
Allergic reactions can cause a range of symptoms. Some allergic reactions can be quite mild, and some are more serious.
An allergy develops when an allergen triggers the immune system – the body’s natural defence against germs and viruses. The immune system behaves as if the allergen was a dangerous germ, and releases special chemicals, called antibodies, to destroy it. It is the release of antibodies which causes the symptoms of an allergic reaction.
Where the allergic reaction takes place depends on how you came into contact with the allergen. Contact may be with your skin, or with the lining of your lungs, mouth, throat, stomach, or intestine. If your body reacts badly to a particular substance, you are said to be allergic to it.
Some of the most common symptoms include the following:
- sinus pain (feelings of pressure or pain high up in the nose, around the eyes, and at the front of the skull),
- runny nose,
- nettle rash / hives,
- itchy eyes, ears, lips throat and palate (roof of mouth),
- shortness of breath