I have lots of these little red bumps with white in the centre on my upper arms what do i do?

ok i have lots of little bumps on my arms and they have white stuff in them i went to the doctors years ago about them ( i didnt have as many) and i ended up getting lots of different meds that didnt work so i eventually forgot about them but now i have heaps and it looks really nasty cause they are red with a bit of white in the middle it isnt painfull or anything but they look bad so what can i do to get rid of them