Pruritogenic pathway in the skin

**Pruritogenic pathways in the skin** refers collectively to the networks of molecular mediators, receptors, and neuronal circuits responsible for sensing, transmitting, and amplifying itch (pruritus) signals. These pathways integrate immune-derived mediators such as histamine, IL-31, IL-17, IL-22, serotonin, proteases (trypsin, tryptase, cathepsin S, kallikreins), and periostin, which can directly activate or sensitize peripheral sensory neurons via receptors such as Histamine H1/H4, cytokine receptors (including IL-31 receptor A complex), protease-activated receptors (PARs, especially PAR2 and PAR4), and transient receptor potential (TRP) ion channels (TRPV1 and related family). Non-histaminergic pruritus–often mediated by cytokines or proteases and their receptors–is responsible for treatment-resistant forms of itch in many dermatologic diseases such as atopic dermatitis and prurigo nodularis. Targeting individual nodes (such as IL-31 signaling, TRPV1, or PAR2) can offer disease- or mechanism-specific therapeutic benefits, but "pruritogenic pathways" as a broad term does not correspond to a single molecular target, receptor, or druggable molecule, making it a mechanistic concept rather than a protein, enzyme, or receptor suitable for canonical drug targeting[1][2][3][4][5].

Other names

Pruritogenic mechanism in the skinItch signaling pathways

Histamine receptor antagonism (H1/H4 blockade); TRPV1 desensitization or antagonism; Blockade of cytokine signaling (IL-31 inhibition); Inhibition of PAR2 or PAR4 signaling (protease-activated receptor blockade)