IMHO one reason for an increase in allergies is that parents do not let their children get exposed to things as much as they did in the past.
One reason that used to be given for children having allergies, when I was younger, was if they had been bottle fed more then Breast fed, that breast
feeding would expose the child to more things they could build up immunity to. Allergies generally happen when your immune system attacks something
you have been exposed to in the environment that it believes is a virus or bacteria. The purpose of getting allergy shots was so the body could get
used to those imperfections in the environment by building up the proper immunity to them in increasing dosages.
Point is that I think back on things that I got into as a kid, and I would never expect a parent to allow their children to be exposed to such things
today. Like catching frogs from a ditch next to a roadway by way of example. Maybe parents just got more protective of their children, or maybe they
just realize the environment got more polluted or unsafe. It could be all the anti-bacterial cleaners that we use now. It might also just be that kids
always had allergies, but there was not much you could do about it until the shots came out in the 70’s.

