How Do You Cure Scalp Itches And Scalp Pimples?

I tend to feel very itchy on my scalp and can’t help but scratch it ALL THE TIME – when I’m at work, when I’m sitting on my bed – my fingers keep reaching in there and picking at it. Does anyone know what I can do to reduce the pimples on my scalp and to prevent the itching. I’m trying this tar shampoo and I tried Nizorol but I’m not seeing enough of a difference. Is it diet related?