Small pimple like rash

i have been on preds for 3 months and successfully reduced from 20 mg to 10 mg.  Now a new symptom.  Small pimple like rash appearing mostly on my arms and legs.  Itchy and swollen then subsiding into red spots.  is this something  to do with pred withdrawal?  has anyone else experienced this?

I know acne is a possible side effect of prednisone, but haven't heard of any rashes. Could it be caused by something else? 

I mentioned a rash but this is more like individual "flea bites".  Thought of acne but these are itchy.   I think I'm getting paranoid about PMR and preds so putting everything down to it.  Possibly a allergic reaction to something else.  Thanks for your help.