Why do people from the West have allergies??

Yes you are right. It's because in the West many of our homes are actually too hygienic, because of all the anti bacterial products we use, and children especially in cities don't go outside enough. Therefore our immune system that would normally be busy fighting germs from the environment turns to attacking other substances, causing allergic reactions.

mj_indigo is right. Our immune systems get bored. People in the East are also allergic to different things than westerners. People are allergic to things that they encounter very often. For example, in Japan, rice allergies are common. In Scandinavia, many people are allergic to cod.

Healthy immune systems react well to allergens, and those those with these healthy immune systems are said to be immune.

If they weren't immune, the individuals would be dead.