What Could Cause Chronic Chest Pain Which Subside Only While Taking Medication For Pneumonia?

I m talking for my fianse who i have begun to really worry about, she has been experiencing chest pain for over a year now, shes been to the ER and to her personal doctor she has gotten several Xrays, a ct, a white and red blood cell test and they all came back positive with the exception of one of the Xrays where they found what might be a spot of pneumonia on the lung they treated it with antibiotics and she said the cheat pain went away for a bit but came back, (that was at the ER). Her personal doctor prescribed her prednisone an anti-inflammatory she said that also helped but after the prescription ended it also came back. Today she is experiencing pain extreme enough that she is crying and doesnt want to move at all please help