Long story short, I got a terrible skin infection on my right index finger, directly next to the nail. I was prescribed Keflex 500mg, 3 capsules a day. So far, I see no improvement whatsoever, in fact, the infection is becoming more elevated and more sensitive. My whole finger has doubled in size and I can hardly bend it all the way down anymore. I've been taking Keflex for 4 days now.