What is causing my outer ear to become bright red?

Posted by missedythe

I have one ear that becomes bright red and warm to the touch. It is just the outer ear (from what I can see), and has been occuring occasionally over the past 6 months, with the frequency increasing over the last two weeks. It does not appear to be swollen, is not [painful (although I can feel the warmth without touching it with my hands). Thanks!