My son is having only cough with no other symptoms, cough gets fine with medication but again returns after medication is over. (Cough is not having any nature sometimes its more in day and sometimes at night, its a dry cough but more like clearing throat kind off) Chest xray is fine, mild adenoid was there, endoscopy done where they find healthy nose throat, no acid reflux problem, adenoid was not the cause. Puff/neublization/syrup/ allegra/montair lc/steroid all he tried but gets relieve for only week. I have already shown him to gastro, ent, pulmonologist, don't know what should I do next, blood test can find something?