Suggest Treatment For Allergic Itchy Skin Rash On Upper Body

i'm taking a round of 20mg prednisone for poison oak - had it close to my eye. after 3 days of 3 tablets each day and now I'm taking 2 tablets for 5 days, i have this rash on my arms and torso and neck and sholders. my skin is very hot and the rash itches like crazy.