Pruritus: Progress toward Pathogenesis and Treatment

Figure 1

The possible mechanisms and neurological pathways of pruritus. Itch stimuli initially induce cells (e.g., immune cells and keratinocyte) in the skin to release many itchy mediators including inflammatory mediators, neuromediators, and neuropeptides. Subsequently, these mediators bind to their receptors, further resulting in the activation of itch-specific sensory neurons. The itch signals are transferred from mechanically-insensitive C-fibers (CMi) called histamine-dependent (histaminergic) or mechanically-sensitive C-type fibers (CMHs) called histamine-independent (nonhistaminergic) signaling pathway, through the dorsal root ganglion (DRG) of the spinal cord, across the spinothalamic tract to the thalamus, ultimately getting to the cerebral cortex.