my first que is - your age??
any skin lesion is there or not?? any rashes, bulla, blister???
if only itching is there without any lesion posibility of shingles
is least likely..
measure your Blood pressure, if it is normal then take pain killer (NSAIDS) and levocetrizine.
if any skin lesion develop or no improvement in itching and headache then consult dermatologist
or physician near to you.
Dr Ramashanker Yadav