Hi
As you mentioned that you are having dry throat ,cough ( severe bouts) due to cold and sometimes you have to spit saliva ( in my opinion this may be mucus or sputum due to cold).
However all these symptoms , mentioned by you may be due to
allergy .
As allergy causes
bronchitis and
bronchoconstriction produces cough ( as in your case ) . Bronchoconstriction produces cough and saliva or sputum .
This is cause of concern but don't worry so much .
Mite , dust , pollen , mold , hay , smokes , fumes , sudden rise and fall of temperature are few predisposing factor responsible for allergy , hence all symptoms .
I usually prescribe monteleukast + bambuterol ( if asthma or
wheezing present ) , if whistling sound don't present I advise them to use monteleukast+
fexofenadine or levocetrizine twice in day till complete cure.
Good luck.