I went for a private allergy test and was told I had sensitivity to yeast and cows milk. I've eliminated these from my diet and after 6 weeks my asthma has improved a lot. I was prescribed Pred, Fostair, Montelukast and Avamys and am on a waiting list for an injection. Now I just have a puff or two of ventalin when I get wheezy and I'm fine.
The thing is after four years of NHS and BUPA care they did not test for this.
I would recommend anyone who suffers from asthma go for a private allergy test.