6 Pruritus and Dysesthesia

Question 1

Peripheral itch mediators include: opioids, gastrin releasing peptide, B-type natriuretic peptide

Answer 1

F

These are the central itch mediators.

Peripheral itch mediators include histamine, pro teases, IL31

Question 2

There is no overlap between chronic itch and chronic pain

Answer 2

F

There is an overlap, involving multiple brain areas, associated neuro mediators and receptors

Question 3

Cross talk between cutaneous nerve fibres and the stratum corneum is the possible mechanism for itch associated with impaired barrier function - ie xerosis, AD

Answer 3

T

Question 4

Nerves in the deep reticular dermis/SC fat do not transmit itch

Answer 4

T

Question 5

Itch is transmitted by Type C fibres that have unusually slow conduction velocities (0.3-1m/sec) and innervate unusually wide territories

Answer 5

T

Question 6

There are histaminergic and non histaminergic C fibres

Answer 6

T

Both are small in diameter, non myelinated. Respond to pain, itch (histamine and non histamine), cowhage, thermal and mechanical stimuli

Other afferent neutrons that convey itch include small, myelinated A-delta fibres and velocity of 2-30m/sec