I freind of mine in the service went to the base barbershop and got a "high and tight". A couple of weeks later he lost a small, dime-sized patch of hair near the back of his neck. It began to spread and when I last saw him, it was bigger than a silver dollar and growing! I never kept in touch with him, but I often wonder if it spread until all his hair was gone.
You never know what you might catch at a barbershop...