The best way to prevent an allergic reaction is to avoid the substance that you're allergic to, although this is not always easy or practical.
An allergy is a reaction your body has to a particular food or substance. Allergies are particularly common in children, but adults can get them too.
Allergy symptoms include sneezing, wheezing and itchy eyes. A life-threatening allergic reaction can also cause swelling and breathing difficulties.
If you have an allergy, try to avoid the thing you're allergic to if you can. Medicines like antihistamines can help ease symptoms if you need them.
Allergies are caused by your immune system mistaking a harmless substance for something harmful. Common triggers include pollen, food and animals.
Page last reviewed: 22/11/2018
Next review due: 22/11/2021