Hi! My daughter, who is 10, was diagnosed with Mersa a couple of days ago from a very infected finger that the tip of it had turned green. It had to be cut and drained, and she was put on Bactrum. Now since being on the antibiotic for two days, she is still spiking fevers, and is complaining of neck and head pain! should I take her back to the Er? Maybe the infection has gotten into her blood stream, or the antibiotic isn't working?