Suggest Treatment For Cough And Runny Nose In Kid

My 6 year old daughter has had a cough, runny and stuffy nose on and off since September. Sometimes it is barky, other times it is productive. She coughs all day, but not at all once she falls asleep. She complains her shoulders and neck hurt and occasionally her chest. We have tried Allegra, the nebulizer, NediMed, and Prevacid. She is 47 tall and about 50 pounds. She had her tonsils and adenoids out in January of 2010. She is allergic to trees.