This is a common parasite die-off/retreat reaction. The herbs or medicinals you are taking to combat the bugs are not pleasing them and they are moving around to avoid what you're using to deter them.
I am almost through my second week of Clarkia and at the tail end of my first week, itching was most noticeable, especially around my nose and my facial area; My ears were itching as well. My conclusions are that increased itching is a sign of parasitic/pathogen die-off/aggravation.
Salt/Cers know that this is a very common reaction because increased salinity levels greatly aggravate the bugs and they move around to either escape their host due to an inhospitable living environment, or are moving to a more comfortable location that is not as highly saturated with a high salinity level.