I have had these bumps on my arms for a few weeks now.
It started as just two little spots on my left arm, and then I forgot about them for a few days.
I looked back at them after a few days and more of them had appeared.
A few weeks later the same thing started to happen on my right arm.
They seem to be in relatively the same place on both arms and don't seem to be spreading.
http://postimage.org/image/cm8pqanuf/
That is my right arm
http://postimage.org/image/gqa6ppd8r/
And that is my left arm.

Apologies for the low image quality, my camera wouldn't work with my PC.