My 3 and half old daughter ,Weight 15 kg ,suffering from dry cough since 3 month ,there is no fever or cold, appetite is good ,playfull. .consulted doctor prescribed alex jr. ,Given to her shown Temporary relief but again ,dry cough started after stoppage of drug.given zyrcold ,azythral, after that omnacortil ,same temporary relief .coughing is more at night,as if she try to gulp sputum.some day she dont cough ,some day she cough a lot..what it could be???some kind of allergy??Plz help??