Among many other...
The skin is the most sensory innervated organ in the body.
Among the many causes of itching, stress
could be a factor, but it is often some very minor sensation that causes a brief itch, and then one scratches and that causes more itching....Dry skin
, allergy to almost anything that touches the skin, or is inhaled will set off a response that allows mast and other cells to release histamines. Itch.