22 female,wet cough for almost 3months;double dose of arithromycin and cefuroxime,antihistamines and a nebuliser dont help;chest xray basal bronchitis and adhesions near diaphragm;auscultation rare rattles;spirometry and feno normal;what could it be?

CT chest +/- bronchoscopy and certain serology tests may need to be done. If you have been evaluated by a pulmonologist then you should seek for a second opinion at an academic center. If you have not seen a pulmonologist then it's time to see one. Community acquired/typical pneumonia and bronchial asthma have been ruled out. Take care and good luck.