Chronic pruritus affects millions of patients worldwide and has a significant impact on quality of life similar to that of chronic pain (Kini et al., 2011; Stander et al., 2007). Significant advances have been made in the last five years to elucidate the molecular pathways of acute itch (Liu et al., 2009; Sun and Chen, 2007). However, experimental approaches investigating the pathogenesis of pruritus and the ability to test novel therapeutic agents are largely limited to rodent models. Although these models offer some advantages, their translational potential to human disease remains to be established (Seok et al., 2013; Jeffry et al., 2011). Furthermore, most animal models focus on acute itch, which displays significant pathophysiological differences in comparison with chronic itch (Yosipovitch et al., 2007). Therefore, there is an unmet need for better animal models for chronic itch research.

Users may view, print, copy, and download text and data-mine the content in such documents, for the purposes of academic research, subject always to the full Conditions of use: http://www. nature. com/authors/editorial_policies/license. html# terms* Correspondence to: Gil Yosipovitch, Department of Dermatology, Neurobiology & Anatomy, and Regenerative Medicine, Wake Forest University Health Sciences, Winston-Salem, NC 27157, Phone:(336) 716-2901, Fax:(336) 716-7732, gyosipov@ wakehealth. edu.