Itchy skin
Introduction
It seems simple. When you itch, you scratch. But itchy skin (pruritus) can have hundreds of possible causes. It may be the result of a rash or another itchy skin condition, such as psoriasis or dermatitis. Or itchy skin may be a symptom of an internal disease, such as liver disease or kidney failure. Though itchy, your skin may appear normal. Or it may be accompanied by redness, rough skin, bumps or blisters.
Identifying and treating the underlying cause of itchy skin is important for long-term relief. Itchy skin treatments include medications, wet dressings and light therapy. Self-care measures, such as anti-itch products and cool baths, can help reduce itching and soothe inflamed skin.
http://www.mayoclinic.com/health/itchy-skin/DS00847/DSECTION=1