What Does The Itchy Bite Marks On Body Indicate?

I have intermitten bites? on my body that itch and scab. It is currently intensley cold and dry where I live and I wonder about that as a cause. However, I recently had a small area on my forarm that itched so much I scratched the skin off which left a scab that is black. Yikes! Are these little mites that live all over, get under the skin and that I could have an alergy to?