A person is more likely to get allergic rhinitis if their parents have it too. This is also true if the parents or any family member have other allergies like skin allergies, asthma or even food allergies. These diseases tend to run in families.
Everybody’s defense system is in charge of checking the things that come into contact with it. It labels normal things as safe and harmful things (like viruses), as unsafe.
Then, the immune system will make antibodies (IgE - as an example) as well as chemical substances - act as inflammatory mediators, such as histamine, to attack the harmful things specifically.
Sometimes, the defense system will make a mistake by attacking a safe substance like tree pollen through those antibodies and mediators. This is what gives a person allergic rhinitis and other allergic reactions.
