Hives from penicillin allergy started 7days ago. the doctor prescribed benadryl+hydrocortisol 4days ago. the skin isno more stiff but redness has spread. normal?

You may have late: Reaction or the symptom did not resolve . You may have secondary infection . I suggest talk to your doc and he /she will evaluate and address the issue for you. Good luck.

Something else: This may not be from penicillin allergy. Perhaps a viral infection was the initial problem and then the rash may last up to 3 weeks . You should consult an allergist after this is over to find out if you are truly allergic to penicillin. Sometimes i would just get a CBC to see what types of cells are abnormal to help establish a diagnosis.