Glial Cells are Involved in Itch Processing

Recent discoveries in itch neurophysiology include itch-selective neuronal pathways, the clinically relevant non-histaminergic pathway, and elucidation of the notable similarities and differences between itch and pain. Potential involvement of glial cells in itch processing and the possibility of glial modulation of chronic itch have recently been identified, similarly to the established glial modulation of pain processing. This review outlines the similarities and differences between itch and pain, and how different types of central and peripheral glial cells may be differentially involved in the development of chronic itch akin to their more investigated role in chronic pain. Improvements are needed in the management of chronic itch, and future basic and interventional studies on glial activity modulation would both enhance our understanding of mechanisms underlying the chronification of itch and provide novel opportunities for the prevention or treatment of this debilitating and common condition.