Skin Itch

Pruritus refers to an unpleasant sensation that causes the need to scratch, commonly called itching by most people. Itching may be localized to a certain area of the body, or can be all over, or generalized. When there is a rash that goes along with the pruritus, the cause is usually easily determined and treated. However, the most difficult cases of pruritus are those without an associated rash.
What Causes Pruritus?
Pruritus and pain are closely related sensations, since the same nerves transmit both signals to the brain. When the area of skin is scratched, that same area may become even itchier, leading to more scratching. This is called the itch-scratch cycle. In general, pruritus can be related to a problem with the skin or another underlying disease of the body (systemic disease). When itching is localized to a particular area of skin, it usually is not caused by a systemic disease.
Localized Pruritus
Areas of itching that are only on one part of the body are more likely caused by a problem of the skin. The area of the body that itches may give a clue as to the cause of the itch.