I was born with a huge blak birth mark with hair on my back and a few small ones on my legs,hands and under my feet. The one on my back itches I went to a dematologist ,but what ever he gave me for the itch did not work. Occasionally the itching stops and then a few months later it starts back up again. Why does this huge one on my back ihctes but the small one on the rest of my body does not?

How old are you?