For the last few months or so random scabs have been appearing on my legs, thighs, tops of my feet, and buttocks. One appeared on my arm but it healed. Most recently, a small, black, round scab appeared on my right leg. They are not from injuries - I have not injured myself at all in the past few months. I am wondering what they could possibly be. Could it be eczema, or something else? Has anyone else experienced something like this?