[Uremic pruritus].
Among the various dermatologic abnormalities that can be associated with advanced chronic renal failure and dialysis therapy, pruritus is certainly the most disturbing disorder. Pruritus is an unpleasant, vexing sensation that provokes an intense desire to scratch. In the past the pruritus was considered from the neurophysiologic point of view as a submodality of pain, but more recent research showed that pain and pruritus are sensations which are carried through different populations of primary sensory neurons. The causes of pruritus in uremic patients are still unknown: xerosis, intradermic microprecipitation of divalent ions, hyperparathyroidism, peripheral neuropathy, allergic reactions and hypersensitivity, histamine and others have been considered as pathogenetic factors. The uncertainty on the causes is in part responsible for the different approach and results, unsatisfactory in many cases. In this paper we will review the neurophysiology, the pathogenesis and the possible therapeutic approaches to uremic pruritus.