What Causes Red Itchy Area Behind Ears?

I have noticed that I have a red area about an inch wide from just behind both of my ears, that runs down in a V shape to the top of my collar bone. There is no pain, itching or swelling at anytime.I am 48 yrs.old and am curious as to this being a possible problem artery or other possibility. I have had no colds, sinus or ear infections.