Small bump on bottom of ear is a tad red it was hard like a pimple like bump but no puss or anything to come out of it what cause this will go away?

Developing a boil: Chances are u had a small bite or injury there & it has become infected. It may turn into a small boil/abscess or ur own resistance may nip it and it may heal on its own in a few days. Topical antibiotics will probably not help as the skin is intact. Nothing much to worry unless the pain keeps increasing, the skin gets redder and there are streaks of infection and redness spreading from that bump.