Pruritus

Question 1

define

Answer 1

itch

Question 2

three mediators of itch

Answer 2

chemical
nerve transmission
CNS mediators

Question 3

what chemicals mediate itch?

Answer 3

histamine
PGE2
ACh
serotonin 5-HT
kellikrein
IL-2
substance P tryptase

Question 4

which nerve fibres mediate itch?

Answer 4

unmyelinated C fibres

Question 5

CNS mediators of itch

Answer 5

opiates

Question 6

four types of itch

Answer 6

1. pruritoceptive
2. neuropathic
3. neurogenic
4. psychogenic

Question 7

define pruritoceptive itch

Answer 7

something associated with inflammation or dryness in skin that triggers itch

Question 8

define neuropathic itch

Answer 8

damage to any sort of central or peripheral nerves causing itch

Question 9

define neurogenic itch

Answer 9

no evidence of damage to CNS but itch caused by opiate effect on CNS

Question 10

psychogenic itch

Answer 10

psychological causes with no detectable CNS damage e.g. delusions

Question 11

management of itch

Answer 11

determine cause

anti-itch treatments

Question 12

anti-itch treatments

Answer 12

sedative antihistamines
emollients
antidepressants
phototherapy
opiate antagonists