I have a red bump on the back of my leg. I noticed it yesterday and it was about the size of a quarter and hard throughout the day yesterday and today it has turned into about the size of my palm. It started off itchy and red but now it s red and tender but not really hard except for little spot right in middle. Did notice a white spot in middle yesterday kinda like a pimple. Also have another spot about size of dime that is red and tender with hard middle?? Was on doxycycline for 10 days about a week ago for bacteria I had. I am a 20 year old female.