I recently noticed a bump behind my ear the size of a pea. There was swelling along the back of my ear and it was read. Well, I already had a doctors appointment, so I decided to ask him what he though it could be. He said that he was not sure... looks like an allergic reaction to something. He put me on the antibiotic Keflex. Well, now, the red has turned to purple, and it is hurting more and I am having headaches. Has anyone ever had anything like this?