[modeless]

> many small exposures to diverse allergens adds up

Yeah, that's a thing. Also you may notice higher sensitivity to allergens if your immune system is fighting off a cold (perhaps even before you're aware of being sick, or even if someone in your household is sick and you don't get it because your immune system successfully fights it off). If you are doing oral immunotherapy it is sometimes recommended to reduce your dose when you are sick to avoid reactions.