Various factors influence the development of an allergy. This could be due to heredity, hygiene, or your lifestyle.
Heredity plays an important role in whether or not you develop an allergy. An allergy itself is not hereditary, but predisposed to it. If your parents both have the same allergic condition, there is a 60-80% chance that you will develop an allergy too.
Hygiene and lifestyle
There is a clear link between your “clean” life and the risk of developing an allergy in your life. Unless you come into contact with all sorts of substances found in a less “clean” environment early in life, your body will not get used to them.
Allergies are therefore more common in the western world than in developing countries. There is even a difference between countries like the Netherlands and countries in Eastern Europe. Skin allergies are also less common in countries where a lot of natural and fresh food is consumed.