Hello. Curious if you have any swelling in your arms, and what your last CBC blood results looked like.
This is something best answered by your doctor, so you can get the appropriate medical advice tailored to your specific condition. My dad had this in his lower legs. It started out as little marks like you described, then over a week or two, turned into a full blown red, raw looking rash. I think it might be a different situation, but they gave him antibiotics. In case it's related to an infection or if you have low white blood cells, that can be especially important to get on it with your doctor.