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Flashcards in Pruritis Deck (14)
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1

Which substances can induce mast cell degranulation?

  1. Substance P
  2. IgE
  3. Allergen
  4. C5a
  5. Opiates

2

What are the four causes of itch?

  1. Pruritoceptive causes
  2. Neurogenic causes
  3. Neuropathic causes
  4. Psychogenic causes

3

Which class of drug is ondansetron?

Opiate antagonist

(for serotonin)

4

What are three classes of itch mediators?

  1. Chemical mediators in the skin - histamine, acetylcholine, substance P etc
  2. Nerve transmission - Unmyelinated C fibres
  3. Central nervous system mediators - Opiates

5

In nerve fibres are exposed (unmyelinated), yet not damaged, which cause of itch is involved?

Pruritoceptive

6

Which cause of itch is associated with damage to central or peripheral nerves?

Neuropathic

7

How can neurogenic itch be described?

Itch which originates in the CNS yet there is no evident damage

8

Insect bite reaction involves which type of itch?

Pruritoceptive

9

What is doxepin?

Antidepressant

10

Which type of antihistamines must be used to treat itch?

Sedative antihistamines (usually first generation)

11

Which anti-histamine is commonly used to treat itch?

Chlorophenamine maleate

12

Pruritoceptive itch can be defined in which way?

Something usually associated with inflammation or dryness in the skin which triggers itch

(e.g. insect bite)

13

Name 3 pre-formed mediators from mast cells

  1. Proteases
  2. Histamine
  3. Heparin
  4. Cytokines

14

Name mediators which are synthesised post-degranulation in mast cells

  1. Prostaglandin D2
  2. Leukotrienes C4, D4 and E4
  3. Platelet activating factor
  4. Cytokines