Hey Widdly, there are some things they can tell from a blood test and other things they need to do a skin test for.

My blood test didn't cost me a thing and I found out I was allergic to dust mites, animal fur, pollen and grass. I never had the skin test done because of the same reason, it was going to be too expensive. If your doc bulk bills you should be able to get a blood allergy test for free.

With the antihistimines, it all depends on each person. Clarantyne for examply is fine for one person but sends me loopy and I can't function properly. most other ones do to, like i mentioned earlier.

A nasal spray is a good suggestion!! I also got some allergy eye drops cause my eyes were red from rubbing them and being itchy and they also really help. Maybe check with the chemist to see if that is safe? They cost me under $10