Hi, Welcome to Health care magic forum. Cough is due to the allergy, or infection, of the lungs. Both are to be treated completely.Benadryl can take care of the allergy, but infection is to be taken care of. I advise you to consult a physician for diagnosis and treatment. I usually prescribe to my patient with such symptoms cifixime, ofloxacin, diethylcarbamazine citrate in addition to benadry. Avoid taking fruits, juices, cool drinks,cool water etc. Wishing for a quick and complete recovery. Thank you.