The things that set off allergic reactions are called allergens. Common allergens are pollen, pets, moulds and dust mites. People can also be allergic to certain types of food – for example, nuts or eggs. It is possible to be allergic to more than one thing.
Eczema, asthma, hayfever and rhinitis are all allergic disorders.
An allergy develops when your body’s immune system reacts to the allergen (for example, grass) as though it is a threat to your health. Your body produces antibodies to fight off this threat. This is called the immune response and this can be your runny nose, itchy eyes or sore throat.
Who has allergies?
Many of the people who have allergies are children. Some allergens, such as foods, are a problem all year long, but others might only bother people at certain times of the year – you might be allergic to pollen from trees, which is only around in the air in the spring.
Anyone can get allergies, but often you are more likely to have an allergy if someone else in your family has them. People can develop allergies when they are babies, children, teens, or adults, although allergies often get less in older people.
Most things that cause allergies are not harmful to people who do not have allergies.
What are the symptoms of an allergy?
Allergens can cause breathing problems like wheezing and shortness of breath. Sometimes people have a very bad allergic reaction and become very ill and need hospital treatment. You can end up with a head full of snot, have itchy eyes and ears, a runny nose, a sore throat and feel like you are spending the whole day sneezing and wheezing. If you are allergic to a certain type of food you may get hives (a red, bumpy, itchy skin rash), a stuffy nose, tummy ache, sickness or diarrhoea. Yuck, yuck, yuck!
For more information about child allergy head over to http://www.allergyuk.org/child-allergy-menu/child-allergy or http://www.nhs.uk/Conditions/Allergies/Pages/Introduction.aspx for more information and useful advice and support.