Itchy ?

Hi Doctor,

I am a 28yo Male , And YES i am a smoker but i will quit this year i am very motivated to not to smoke in 2008.
Here is my problem ,

In my Throat or in my lungs, Right inside of my chest there is always something disturbing.Its itching 24/7 , It is not making me cough but you know when i cough deeply it kinda goes away for 2-3 hours.I went to my Doctor ( Fam. Prac.) and he said he thinks it`s allergies so he gave me Nasonex and Benzonatate for coughing , which Nasonex seems like to help with it after spraying it for 7 days non stop in to my nostrils.

Do you think its smoking ? or mym says in my childhood i had bronchidal allergical asthma,I couldn`t even touch pets when i was between 7 and 12 years old ? but it went away,i had no symptoms at all since this age.But this thing has been going on for the last 8-10 months ? just a disturbing itch right behind my chest and when i pull REALLY strong coughs it goes away for 3-4 hours but comes right back.

Again Mom thinks its the detergents,smelling candles,Febreeze essences etc.
Could you please tell me your thoughts as an expert on allergical symptoms?

Thanks a lot.