Now I am in my 40's and have wicked insomnia, and I smoke to help me sleep. It no longer makes my allergies go into high gear. Surprisingly, if I stop smoking for a few days, then my allergies go into high gear and I become a phlegm/mucus factory. When I start smoking again, my allergies calm down. WTF!
Can anyone explain this to me? It makes no sense to me that 20-25 years ago smoking would trigger an allergy attack, but now NOT smoking triggers allergy attacks and smoking helps alleviate said allergy attack.

I'm hoping someone who understands how allergies work might be able to make sense of the whole situation.