Hayfever but treatment doing nothing

[lotsofthingstolearn]

So, DS aged 11 but 165cm and 63kg is under respiratory consultant. (Controlled asthma)

But, he also has pretty bad hay fever and prescribed nasal steroid, drops and fexofenadine 120mg

He is worse than ever, is there anything else that can be done- or is this his miserable summers for the foreseeable?

Also forgot to add, regular sterimar to try and flush his nose.