Definitely use good moisturizer to eliminate xerosis (dry skin
) as the cause.
I prefer cetaphil or cerave cream 1-2x daily (not lotion). If it is localized to the middle of your back , it may be a condition called notalgia paresthetica which is best described as nerves misfiring and causing itching. No great treatment, may apply pramoxine a few times a day. Also, if focal may have itchy growth.