I have had hives for 4 days, since Thursday. I was prescribed prednisone on Saturday. I took 60 mg Saturday, 60mg Sunday & 60mg this morning. My hives have not subsided. How long does it take for the prednisone to work? I have also been taking benadryl every 4 hours.. So miserable need relief..The Doctors office closed today so cannot see her. Thanks.