pruitus Flashcards
1
Q
what is itch (pruitus) definition
A
a usually unpleasant, poorly localised, non-adapting sensation that provokes the desire to scratch
2
Q
what can mediate an itch
A
- chemical mediators in skin eg histamine, PGE2…
- nerve transmission - unmyelinated C fibres
- central nervous system mediators - opiates
3
Q
what causes itch
A
- pruritoceptive: something (usually associated with inflammation and dryness) in the skin that triggers itch
- neuropathic: damage of any sort to central or peripheral nerves cause itch
- neurogenic: no evident damage in CNS, but itch caused by eg opoaye effects on CNS response
- psychogenic: psychological causes with no (currently detectable) CNS damage eg itch in delusions of infestation
4
Q
how to manage itch
A
- determine cause if possible
- treat the cause
- anti itch treatments: sedative anti histamines , emollients, antidepressants, phototherapy
