To help with dry scalp, after your evening bath, gently brush your hair with a quality hairbrush for one minute, concentrating on your scalp more than anything.
Not too aggressive, but firm enough where your scalp feels refreshed and alive when you're done.
It will take a week, possibly two, before you notice the results, but the itchy dryness will diminish and eventually cease to exist.
My husband doesn't do anything with his hair, because it's naturally wavy and super thick, so he doesn't comb or brush it ever, he just pulls it into place with his fingers and a little water, and he suffers from itchy scalp once the cold of winter hits, and after I turned him onto giving his scalp a regular massage through brushing, he no longer suffers from itchy or dry scalp.