I Have Developed Painful Sores On The Back Of My

I have developed painful sores on the back of my scalp, toward the neckline. They have formed in a cluster and are raised and sore to the touch. I have a tendency to pick at them, so I may be further irritating them, however there is also soreness in my neck right below the curve of the back of my head. Can you give me an idea of what this may be?