chronic cough

[cring]

Hi!!! My fiancee has been having really loud and dry cough since 9 months ago.  We went to several doctors and the only thing that they could say is that it could be allergies, asthma or hyperacidity.  He is feels nauseous and throws up quite often.  He has been given medications for asthma (advair, albuterol, a prescription steroid he took for 5 days) and also for his allergies (claritin).  Nothing seemed to work.  He also takes a medication every morning for his hyperacidity.  Still his cough continues.  I noticed that it is worse at night.  He doesn't cough in the morning, or if he does, it is very minimal.  His chest x-ray is clear and we are still awaiting appointment for his asthma test (to prove that he really  has asthma).  He says that he coughs because he feels like something is stuck in his throat.  He doesn't have chest pains or phlegm.  

Please help!  Nothing really works!

Thank you!