My asthma doctor, that I had in the past, told my mother that smoking masks, or covers up, allergies. This helped me out when I had an allergic reaction to ibuprofen. My throat started closing up and I had trouble breathing. I had a smoke immediately and these reactions went away, thank goodness.Another thing, that I've been pondering lately is, that since 1980 I had a nasty hay fever in the summertime.
In '89, when I moved away from home, I started smoking. It must have been the last years of 90's, when it suddently went away.