not sure about the itching.

Boils-tumeric herb

Try bepanthol cream from a pharmacy.
They use it when you make a tattoo for your skin to regenerate as it has B5 vitamin.
It costs about 6 euros.

I had it for treating a tattoo and when someday boils appeared that was itching in my chest (they troubled me for over a month) applyied experimentaly and the itching stopped within hours and the boils disappered in a couple of days.

It doesn't work for the scalp but whenever there is itching try it and you will be amazed. I came into this accidentally but works wonders. It only costs 6 euros. Try and give us your successful feedback in hours (and I think itching goes for ever).