I recently had skin cancer removed on head. When I took the antibiotics for this, I got elliptical red marks about 1 1/2 inch long and 1 inch wide, pointed at the ends like a marquis diamond for a ring, at the top of each breast. They are almost identical, with regular skin inside and the red outlines are about 1/4 wide, a little narrower in some areas. What could cause this? Why would they appear on both breasts? Why would they almost be the identical same size? I ve had lots of rashes and skin problems, but this is weird.