Are you allergic to going outside?

I watched a grand designs episode where the parents (well, inflicted by the wife) Munchausen by proxied these allergies onto their kids. They were obsessive about having an allergy free house and spent hundreds of thousands building one with, basically a lesser version of what you explained up there.

Revisiting several years later, the children had integrated with society (amazing that they weren’t homeschooled) and lo and behold - allergy free.

The provocative host coaxed out of the parents that they believed that the house did bugger all in terms of helping their children.

I wonder how the kids are doing now without their namby mother