How To Treat Clusters Of Small Red Bumps On Leg?

I have had these little red bumps on my right leg for over a month. They do not hurt or itch unless I touch them. I have two clusters of them, one on my thigh and one on my calf and I just want to get ideas on what it could be. One other thing is they are becoming whiteish in the middle, but it's not acne. What could it be?