I'm getting EXTREME itch on my arms and legs and I don't know why. Small white stuff appears when I scratch my skin. I've tried narrowing it down to a few reasons without luck. E.g., it used to itch ONLY during and after taking a bath. But over time (it's been happening for over a year) my arms and legs just gets extremely itchy all of a sudden, usually at night, and lasts for 30 mins 1hr. I would appreciate any help. I tried everything, from changing towels, shampoos, soap, even moisturizer.