Pruritus is common complaint in dermatology, which can affect psychological and physical aspects of life. It is estimated that as many as one-fifth of the worlds population experience chronic pruritus, which affects the quality of life. An understanding of the pathogenesis and diagnostic approach of pruritus is needed to determine its management. The exact mechanism of pruritus is remain unclear, but recent studies have shown that several mediators, signaling pathways, and neurotransmitters play role in itch sensation. Mediator-related pruritus demonstrated the role of amines (histamine, serotonin), interleukins, proteases, peptides (bradykinin, substance P, opioid peptide) and phospholipid metabolites (cannabinoids, eicosanoids, platelet-activating factor) in the development of pruritus at different stages. Two signaling pathways identified in the mechanism of pruritus are histaminergic and nonhistaminergic pathways. The itching stimulus induce the cells in the skin to release mediators, which will bind to their receptors and activate itch-specific sensory neurons. The itching signal will be transferred via histaminergic or nonhistaminergic pathway, through dorsal ganglia in the spinal cord, spinothalamic tract, thalamus, to cerebral cortex, which will eventually produce pruritus.

pathogenesis

pruritus

sensitive skin

human and health