Potential new therapeutic targets for pathological pruritus.

Very few approved medications are indicated for the treatment of pruritus, and drug development for pruritic diseases is awaited. During the past two decades, progress has been made in understanding the molecular basis of the physiology and pathophysiology of pruritus. Newly identified potential targets for pathological pruritus include receptors (histamine H4 receptor, leukotriene B4 receptors, interleukin-31 receptor A, bombesin BB2 receptor, toll-like receptor 3, α-adrenoceptor, and opioid μ- and κ-receptors), channels (transient receptor potential (TRP) V3 and TRPA1 channels), and enzymes (histidine decarboxylase, sphingomyelin glucosylceramide deacylase, 5-lipoxygenase, leukotriene A4 hydrolase, and autotaxin). The development of specific, effective blockers and agonists/antagonists of these targets is awaited.