The agent of our immunological misery is the disappearance of something we co-evolved with in a mutually beneficial relationships: microbes and parasites that have lived inside our bodies for millennia.
This new hypothesis is brilliantly summarized in a recent book by Moises Velasquez-Manoff: An Epidemic of Absence: A New Way of Understanding Allergies and Autoimmune Disease.
~ Todd Becker from, http://gettingstronger.org/2013/03/what-causes-allergies-and-autoimmune-disease/
ɕ