M.P.
I sympathize with you. I'd hate to have people asking me all the time. What ever happened to manners?
Have you asked a dermatologist? Unless someone has experienced this, I doubt that they would know and this is not a common experience. My granddaughter has white lines on her arms from when she's scratched. She has eczema. But they tan the next summer. They're visible for probably a year at the most.
My daughter has a white spot on her leg and the doctor diagnosed it but I don't remember the term. It will always be white because the pigmentation is not in that part of her skin.