Immunology

Question 1

Keratinocytes in epidermis function

Answer 1

Sense pathogens - activated by UV/sensitisers
Produce AMPs to kill cells (psoriasis)
Produce cytokines/chemokines

Question 2

AMPs found at high levels in:

AMPs at low levels in:

Answer 2

High in psoriasis

Low in eczema

Question 3

Langerhans cells in epidermis function

Answer 3

Immune dendritic cell
APCs with birbeck granules
Activate T cells

Question 4

Type of T cells in epidermis

Answer 4

CD8

Question 5

Type of T cells in dermis

Answer 5

CD4 and CD8

Question 6

TH1 cells found in:

Answer 6

psoriasis

activate macrophages

Question 7

`TH2 cells found in:

Answer 7

eczema

help B cells

Question 8

TH17 cells found in:

Answer 8

psoriasis and eczema

Question 9

Other cell types in dermis

Answer 9

Macrophages
Neutrophils
Mast cells

Question 10

MHC class 1

Answer 10

Found on all cells

Present endogenous Ag to cytotoxic T cells

Question 11

MHC class 2

Answer 11

Found on APCs

Present exogenous Ag to helper T cells

Question 12

Diagnosis of allergic contact dermatitis

Answer 12

Patch testing

Question 13

Treatment of allergic contact dermatitis

Answer 13

Avoidance
Anti-histamine
Steroid

Question 14

Non-immune cells of epidermis

Answer 14

Keratinocytes

Question 15

Immune cells of epidermis

Answer 15

Langerhans cells

CD8 cells

Question 16

Other cells of epidermis

Answer 16

Melanocytes

Question 17

Immune cells of dermis

Answer 17

Dendritic cells, macrophages, CD4, CD8 cells, NK cells

Question 18

Other cells of dermis

Answer 18

Fibroblasts

Lymph/vasculature

Question 19

Presentation of urticaria

Answer 19

Itchy
Lesions appear within 1 hour
Lasts 2-6 hours
Hives, wheals, nettle rash

Question 20

Presentation of angioedema

Answer 20

Localised swelling, non pitting oedema

Not itchy

Question 21

Investigations for allergy

Answer 21

RAST (specific IgE)
Skin prick
Challenge test
Serum tryptase levels

Question 22

Treatment of allergy

Answer 22

Avoidance
Anti-histamine
Steroids
Adrenaline
Mast cell stabiliser (cromoglicate)
Immunotherapy
Medic alert bracelet

Question 23

Adrenaline autoinjector

Answer 23

300ug adults
150ug kids
2 pens per patient

Question 24

Non-allergic reactions

Answer 24

Direct mast cell degranulation, e.g. lactose intolerance

Question 25

Example of type IV

Answer 25

Allergic contact dermatitis | Onset after 24-48 hours

Question 26

Where is itch processed?

Answer 26

Forebrain and Hypothalamus

Question 27

Chemical mediators of itch

Answer 27

``` Histamine Heparin Cytokines PG ACh Serotonin IL2 Substance P Tryptase ```

Question 28

Nerve transmission of itch

Answer 28

Unmyelinated C fibres

Question 29

Pruritoceptive itch

Answer 29

Something in skin triggers itch, e.g. eczema

Question 30

Neuropathic itch

Answer 30

Damage to nerve, e.g. post shingles

Question 31

Neurogenic itch

Answer 31

No CNS damage but itch through CNS receptors, e.g. opiates, liver failure

Question 32

Psychogenic itch

Answer 32

Psychological causes, e.g. Morgellans (nanoparticles)

Question 33

Treatment of itch

Answer 33

``` Sedative anti-histamine Emollient TCA Anti-epileptic (neuropathic) Phototherapy Opiate antagonist (ondansetron) ```

Question 34

Food allergy

Answer 34

Symptoms caused by immune reaction (IgE) Acute Itch, red, urticaria, angioedema, sneezing, SOB, wheeze N+V, colicky pain, diarrhoea

Question 35

Food intolerance

Answer 35

Non-immune reaction e.g lactose intolerance Delayed Itch, red, eczema GORD, diarrhoea, blood, abdo pain, fatigue, pallor, faltering rowth