Pruritus is quite simply itchy skin. Pruritus can be a part of skin diseases, internal disorders, or due to faulty processing of the itch sensation within the nervous system.
Pruritus may be caused by a number of conditions such as contact dermatitis (an allergic skin reaction to something such as poison ivy, perfume, soap, etc.), urticaria (hives), varicella virus (chicken pox, shingles), eczema, dry skin, parasitic infections (ringworm, scabies). More serious causes include hepatitis (due to the accumulation of bile salts beneath the skin), hyper- and hypothyroidism and iron deficiency anemia.