Suggest Treatment For Persistent Cough And Cold

Hi my daughter has been having severe bouts of cold & cough since 31st January 2010, I've seen best pediatricians to date, but in vain. They give her anti-biotics & other anti histamines and the symptoms sometimes get better, but return after 3-4 days. She was also put on steroids to relieve her violent cough, and she got better. She is again down with a bad cold, the doctor say, she has acute rhinitis, sinusitis & a soft tissue tenderness. Can someone please advice me how to go about this nagging issue & get an accurate diagnosis. She is also marked absentee in school coz of this problem, I am a worried mother looking for a desperate answer.