After taking generic Keflex for 13 days;500mg3xday; i developed a severe skin rash on legs,arms, neck,back,face,eyes,ears,and nose.Was taking med for a serious infection on top of my foot;(same foot bit by brown recluse spider in 2002).Also feel weird all over. Foot infection getting worse and DOCTOR knew i was allergic to penicillin and so did pharmacist.DON'T PLAN ON TAKING THIS MED ANYMORE!!!!! gk65.