Dehydration will cause your skin to be dry and flaky and itches , just like what we call winter skin, and can also cause your sips to be very dry, chapped and red from the dryness, but the way you describe your symptoms, you have something systemic going on,, like an allergy.
Operating Standards are a set of guidelines or regulations that people have to meet or exceed while in operation. It makes sure that the product that they produce is of acceptable quality for consumption by the public.
An operational definition is generally designed to model a theoretical definition. The most operational definition is a process for identification of an object by distinguishing it from its background of empirical experience. The binary version produces either the result that the object exists, or that it doesn't, in the experiential field to which it is applied.