Since the sensations are occurring all over the body, it is unlikely to be due to contact dermatitis or sunburn, especially, since the itching stops when you scratch. It is more of a generalised neuropathy (problem of the nerves).
The commonest cause of generalised neuropathy is deficiency of vitamins of the B group, especially Vitamin B1, B6 and B12. These vitamins are responsible for maintaining of the integrity of the nerves - any deficiency can lead to these nerves getting irritated.
Other causes of generalised neuropathy can be eczema (you will get associated severe dry skin), motor neurone diseases and myopathy (you will get weakness of the muscles).
I think a course of high strength multivitamin multimineral supplements will work for you. Also please increase the intake of raw friuits to get the vitamins in the natural state as these are more readily absorbed in the body.
I hope this helps.
I don't think you have myopathy - if you had you would have had a lot of other symptoms.
Yes, the itching can definitely be related to your menopause. Decreased estrogen level in the body causes a mild thinning of the skin with increased sensitivity. It also causes dryness.
This is also the time when the digestive system becomes sluggish and absorption of nutrients from the gut decreases. Chances of deficiencies are also more.
A nutritional supplement, increased water intake and adequate moisturising of the skin should help you. Please avoid cortizone or other steroids as far as possible - they cause the skin to become even drier. If the itching becomes unbearable, try applying an cold pack over it ( a folded towel placed in the fridge works well).