Diabetes is often thought to be an endogenous cause of pruritus, but in fact most people with diabetes do not experience pruritus. If this does occur, the first thing to look for is the presence of a primary skin lesion or the presence of another cause. The more common causes of pruritus are liver diseases such as obstructive hepatitis and the itching caused by these systemic diseases is also usually generalised, usually confined to the palms of the hands in a relatively small number of cases.