Capsaicin-sensitive cutaneous primary afferents convey electrically induced itch in humans.

Specially designed transcutaneous electrical stimulation paradigms can be used to provoke experimental itch. However, it is unclear which primary afferent fibers are activated and whether they represent pathophysiologically relevant, C-fiber mediated itch. Since low-threshold mechano-receptors have recently been implicated in pruriception we aimed to characterize the peripheral primary afferent subpopulation conveying electrically evoked itch in humans (50Hz stimulation, 100μs square pulses, stimulus-response function to graded stimulus intensity).