My 5 year old daughter keeps complaining all week that she is itchy all over, but no sign of rash. What could it be?

Dry skin. She may have mild allergies. Some infections can cause the skin to itch but without a rash. Either way this should resolve on its own. Dry skin can also cause itching. If it doesn't resolve then see your dr.
Dry Skin. It could be dry skin, or perhaps a very mild irritant from a new laundry detergent or soap.