Since the itching is present over the whole body and that too without any visible rash
, so I would like to rule out dry skin
or xerosis in your case. Dry skin
usually results from environmental factors that you can wholly or partially control. These include hot or cold weather with low humidity levels, long-term use of air conditioning or central heating, and washing or bathing too much.
Take some anti itch lotion and apply it all over the body.