Someone help how long is this itchy ras going to last??? I took 500 mg once a day for 3 days before I stopped taking it.. It has been 4 days rash is on my breasts, thighs and stomach. It is itchy I'm ready to tear my skin off. I tried creams & over the counter meds. Someone just tell me when is it going to stop.. I hate Cephalexin!!!!