Pollen, dust mite faeces (tell it like it is, you're allergic to the faeces of dust mites), don't know what else. Which type of pollen I don't know. Used to get allergic reaction at a certain time of year limited to antihistamines needed for 2 months now I get it bad on and off all year. Last 2 years buddleia caused major reaction but nothing this year. This year old somethings been causing reactions for both me and my partner quite badly. All local too. We both drove home from other end of England and coming off the motorway 1.5 miles from home we both got an immediate reaction, dry eyes. Very uncanny how it happened.
Basically doubt I'll ever be able to limit antihistamine use to a fixed, bad reaction period.
What's odd is asthma only started this summer for me and only badly recently when the morning temp got to about 6C. Although I've always woken up coughing badly, especially in colder times such as camping Autumn or early spring.
The only change in lifestyle is that I'm commuting more this year, in fact I've done 4 days commuting a week pretty much all summer long. This hints at my asthma having a correlation to riding in town. I just suspect a mask might reduce inhaler use. I'm kind of loathe to use.drugs if I've got some other means to control a condition. However if the mask isn't user friendly that won't work. Cold air is easily covered with buffs, used already, but not pollution or particulates though. Would be good to control them If the solution isn't too uncomfortable.