Bump On Neck, Bleeding When Touched. Wearing Headphones Regularly, Have Nickle Allergy. Suggestions?

hi i have this small bump on my neck, it sometimes gets irritated, at first i thought it was a pimple or black head but now it starts to bleed when touched and it bleeds alot but stops after it closes up again, i wear headphones regularly too but i wipe them down with cleaning solution once a week, i also have a nickle allergy aswell, i just want to know what it is, i also think it might be a mole that just sticks out abit from the skin