pruritus pathogenesis

Question 1

Two subsets of pruritoceptive C neurons responding to___

parallel pathways activate

Answer 1

histamine and cowhage,

distinct spinothalamic tract neurons

Question 2

peripheral Itch mediators

Answer 2

histamine, proteases, interleukin-31

Question 3

centrally

Answer 3

opioids, gastrin-releasing peptide receptors

Question 4

overlap between chronic itch and chronic pain

Answer 4

including activation of multiple brain areas and associated neuromediators and receptors (e.g. nerve growth factor, neurotrophin 4, transient receptor potential vanilloid [TRPV] receptor)

▪ Significant cross-talk between cutaneous nerve fibers and the stratum corneum is a possible mechanism for pruritus associated with impaired barrier function (e.g. xerosis, atopic dermatitis)

▪ Combination therapies with typical and systemic drugs that reduce itch sensitization by counteracting the responsible mediators represent promising treatment strategies