I agree with others, I don't think it's the system itself. I think it is either:

contact dermatitis~ if the itching is centered around where the glue/tape is.

the shaving ~ if the itch is all over, it is probably where you are agrivating your skin by shaving it, and then it seems to grow progressively worse as the sweat 'sets' on it, and further irritates it

heat ~ If you are using a cap or something too much it may be holding the heat in too long and simply giving you a heat rash of sorts

Hope it all works out for you soon!