title: Neurophysiology of pruritus: cutaneous elicitation of itch.
abstract: Itching is defined as an unpleasant cutaneous sensation leading to the desire to scratch. It serves as a physiological self-protective mechanism as do other cutaneous sensations like pain, touch, vibration, cold, and heat to help defend the skin against harmful external agents. Pruritus can be evoked in the skin directly by mechanical and thermal stimuli or indirectly through chemical mediators. It may also be generated in the central nervous system independently of peripheral stimulation. Single-nerve-fiber recordings have shown that histamine-evoked itch is transmitted by selective slow-conducting subpopulations of unmyelinated C-polymodal neurons. Recent experimental studies using improved methods have demonstrated which of the suspected chemical itch mediators such as histamine, neuropeptides, prostaglandins, serotonin, acetylcholine, or bradykinin act pruritogenically on C-fibers. Moreover, investigations have revealed new receptor systems such as vanilloid, opioid, and cannabinoid receptors on cutaneous sensory nerve fibers that may modulate itch and thereby represent targets for antipruritic therapy. This review focuses on the peripheral generation of itch, including neurotransmitters, neuropeptides, and inflammatory mediators.
authors: Department of Dermatology, University of Münster, Münster, Germany. sonja.staender@uni-muenster.de
authors: Sonja
authors: S
authors: Ständer
authors: Martin
authors: M
authors: Steinhoff
authors: Martin
authors: M
authors: Schmelz
authors: Elke
authors: E
authors: Weisshaar
authors: Dieter
authors: D
authors: Metze
authors: Thomas
authors: T
authors: Luger
mesh_terms: D006801:Humans; D008407:Mast Cells; D009412:Nerve Fibers; D009420:Nervous System / Q000503:physiopathology*; D011537:Pruritus / Q000503:physiopathology*; D012867:Skin / Q000294:innervation / Q000503:physiopathology*