Chronic cough for 9 months. pulmonary testing suggests no asthma. 3 courses steroid and steriod inhaler. no improvement. wbc normal clear chest x-rays?

Other causes: 95% of chronic cough is caused by one of the following: asthma, reflux, or allergies. Allergies cause inflammation in the nose and sinuses, and your airway responds uniformly. Reflux does not have to actually come up into your mouth or go into the lungs to cause a cough. It can stimulate the nerves that the esophagus share with the diaphragm. I would investigate the causes other than asthma.