How Causes Itchy Tiny Rashes In Both Earlobes?

hi, im rob 37 y/o, i got an itchy, tiny rashes, burning both earlobes(it happened same time), i applied anti-itch ointment for 4days now but still little itchiness occurs, burning and rashes feelings still there, before it happens i'm using minoxidil for my hair regrowth then put some before and after work out in the gym, i used hat during my work out maybe close in contact with my hat?thanks doc