Generalized itching can be due to allergy—you may or may not have accompanying rash
. Common allergens are pollen, mold, dust, pet dander, synthetic fiber, food, cosmetics (powders, soaps, shampoos—see if anything was recently changed) or drugs. Food allergies like to gluten, lactose, sea food, and alcohol etc too should be looked into. It could also be due to new soap, talcum powder, clothes etc. You must get an allergy test done, either a skin test or RAST, to know what you are allergic to.