The thing about asthma is that it has so many factors that might be triggers. Plastics and wall to wall carpet are both worth avoiding if you can. You can get metal lunch boxes for school instead of plastic. Same with water bottles.

What triggers one person won't trigger another. So maybe start with eliminating the sulphites and additives and see how you go.

GAPS...... most people I know who have been on GAPS long term complain of having low energy and seem to take supplements for it so I'm not convinced that it's a great diet for children. They have high energy needs.