Help me out? Me out? any suggestions?

I had coughing problem with sneezing and running nose for last 4 months. First I thought that it was a normal cold and went to doctor, he asked me to take a blood test and the result showed that i have dust allergy. And then he prescribed me histafree tablet for one month. For one month i felt good and later when I stopped taking histafree tablet , that problem raised again. And then i went to other doctor and explained everything, he asked me to take xray of chest and nose. Later he said me that i have allergy in nose and because of this allergy a mild block in airway passage had been formed and wheezing is formed. And he prescribed me inhaler and telecast f tablet for 30days. I have been using it for 20days. At present I don't have sneezing problem , but the coughing problem still exist. Using inhaler for this problem is advisable?? Can you help me out? Any suggestions?