I keep an emergency supply of antibiotics. At the first sign of infection, I start this antibiotic and call my PCP. I have had fibriotic lymphedema in my arm for 12 years following radiation. I have had numerous infections of cellulitis, many of which have become septic. A septic infection takes a minimum of 4 days to treat. Please do. Not wait. Has it ever been cultured? I would suggest that so antibiotics will be chosen carefully for succe#s.