i found a solution! but your case might not be the same as mine..
i surfed the net for 3 whole hours and came up with the perfect solution for me and the bumps went away in 2 days!!!
the cause (for me, at least) was due to too much exposure to the sun ray.
Just put daily moisturizer in the morning and before you go to sleep, put some more on
it should go away quickly! hope it helped!