For a case with a long-established itch, I think first of Qing Ying Tang (Clear the Nutritive Decoction). It's a safe and regularly effective jumping off point for skin problems and possesses complex immune modulating and antimicrobial activity.
Qing Ying Tang is especially appropriate when you have to press relatively firmly on the femoral artery to feel its maximum beat strength; and when the tongue appears red to dark red or purple.
It works synergistically with Nettles, and would be expected to help where Nettles is helping.
Hope that helps,
Steve