I have several rows of small purple dots under my chin, where my neck begins. I can't feel them, and they don't itch. They seem to be in lines although they are not all the same size. I had a mild concussion earlyer this month but other then pain at the site I have had not other issues and I am taking no medication. I doubt the two are related but I think it is worth the mention. I would like to know what this could be.