Every now and then I will get 1 small(3mm) red spot on my penis (on the head or upper shaft) that will stay there for up to 2 months. I've been to a couple dermatologists that have said that it's nothing and not to worry about it. I have tested negative for all the stds that they suggested to test for. But it has been a couple years now and the spot will still randomly show up and stay there for months. usually once it goes away another one will show up in a different place. It's really only annoying visually as there really aren't any symptoms from it. no pain. no puss. every now and then there is some dried/dead white skin on it. Does anyone have any idea what it is?