Dry skin usually results from older age or environmental factors such as long
of air conditioning or central heating, and washing or bathing too much.
Skin conditions and rashes. Many skin conditions itch, including eczema (dermatitis), psoriasis, scabies, lice, chickenpox and hives. The itching usually affects specific areas and is accompanied by other signs, such as red, irritated skin or bumps and blisters.
Internal diseases. Itchy skin can be a symptom of an underlying illness.