hello, i am 47 my name is Phil and 3 weeks ago i walk up with indications of a rash in my chest and belly, i went to see a doctor in my urgent care and they provide me diphenhydramine, and then i went to my regular doctor and he changed to Prednisone. I went yesterday again and another doctor check me and continue the treament with Prednisone and also add it SMZ/TMP DS. because he saw infection in my knees, what can i do? i am already afraid to continue taking more medicine, they don t even check me to see what i am allergic to.