Suggest Remedy For Red Blotches In The Leg

Jsut recenty, I started to see red blotches on my legs with little puss heads. They are a little painful when touched and they go away from time to time. Only one or two come up at once and then it later dries out after a few days and leaves a darken spot on my skin. I also realized my mother and grandmother have the same issue so it must be hereditary. Do you have an idea of what it is?