Actually, what I have is an allergy that they can't detect, but apparently I don't have asthma, just low resistance to chest infections. Why this should hit me hardest at the change of seasons, particularly in winter, is not clear at all. Maybe I'll try some digging. Still, cetirizine hydrochloride works even if it does make me a bit gormless.
The other thing is that I just got a phone call offering me a new job, on promotion with a 25% pay rise (into the 40% tax band) at BERR. I didn't think I'd done a particularly good job at the interview, having had to take antihistamines beforehad, but I did make my prospective line manager laugh. Hurrah.