You might have to go to the pharmacist and get one of those anti itch creams, i have no idea though if in using that medication whether or not it could interfere with the glue/tape adhesion.
I detach after 3 days but its because i also play a lot of sport and just love a good head scrub and shampoo to feel totally clean as i can't stand the feeling of accumulated sweat on my scalp, but that's just me.

Hope you can find a way to cure the itchy scalp.