Red streaks, subdermal bleeding?

[squeezedelf]

Occasionally, when I scratch my skin, it appears to damage the capillaries directly under the skin causing small blotches of blood under the skin. When I go to a doctor, the don't touch it or swab it. They look at from a cross the room and say it's a rash and give me itch cream. It doesn't itch. Never did itch. I'm thinking it is because of thin skin and fragile vessles but not sure of possible reasons. It has been happening since age 17.