There are 3 major reasons for chronic cough. They would be GERD, asthma, or post-nasal drip. Assuming infection has been ruled out (i.e. bronchitis and pneumonia), you may want to consider being evaluated for some of these causes.
They would be an upper GI series and/or 24-hr pH study to evaluate for GERD, a PFT or asthma testing looking for asthma or sinus films (or CT scan if the films were negative) looking for sinusitis leading to post-nasal drip.
The lump in the throat can be suggestive of GERD - so I would consider leaning in that direction. A 24-hr pH study can be considered if the symptoms are not alleviated with the Nexium.
I would discuss these options with your personal physician.
Followup with your personal physician is essential.
This answer is not intended as and does not substitute for medical advice - the information presented is for patient education only. Please see your personal physician for further evaluation of your individual case.
Kevin, M.D.
Medical Weblog:
kevinmd_b