Pimple Type Rash On Arms. It may spread quickly. If youre not sure its keratosis pilaris.

Cellulitis causes red painful tender hot swollen skin and may or may not be accompanied by oozing blisters red spots or skin dimpling. At that point it looked. A rash may cause spots that are bumpy scaly flaky or filled with pus.
A folliculitis infection may start out as small whitehead pimples around one or more hair follicles 4.
They are most likely to appear on your face back chest and shoulders especially where the oil glands in skin are most active but can occur anywhere on your body including your lower arms. On my arms it started out on my wrists and quickly progressed to my forearms as well as to the palms of my hands and the backs of my hands. Naturally you will experience rashes on the arms and legs. It may spread quickly.