Skin Pathology Rashes

Question 1

Where are langerhans cells located in the skin?

Answer 1

In the upper and mid-epidermis

Question 2

Types of collagen that make up the dermis

Answer 2

Type 1 and type III

Question 3

Where would you find ground substances- hyaluronic acid and chondroitin sulphate

Answer 3

The dermis

Question 4

Type of collagen in reticular dermis?

Answer 4

Type 1

Question 5

This part of the dermis contains appendage structures - sweat glands and pilosebaceous units

Answer 5

Reticular dermis

Question 6

What is the epidermal basement membrane made of?

Answer 6

Laminin and collagen

Question 7

Parakeratosis

Answer 7

Persistence of nuclei in the keratin layer

Question 8

Lichenoid-basal layer damage

Answer 8

Lichen planus

Lupus

Question 9

Spongiotic-intraepidermal oedema

Answer 9

Eczema

Question 10

Munros Microabscess

Answer 10

Cardinal sign of psoriasis!

Question 11

Aetiology of acne

Answer 11

1. Increased androgens at puberty
2. ?? Increased androgen sensitivity of sebaceous glands
3. Keratin plugging of pilosebaceous units
   Infection with anaerobic bacterium corynebacterium acnes.

Question 12

Patchy inflammation with which type of cells in Rosacea?

Answer 12

Plasma cells

Question 13

Most common type of pemphigus?

Answer 13

Pemphigus vulgaris

Question 14

IgG auto-antibodies against desmoglein 3?

Answer 14

Pemphigus vulgaris

Question 15

What does desmoglein 3 do?

Answer 15

Maintains desmosomal attachments

Question 16

Intra-epidermal IgG

Answer 16

Pemphigus vulgaris

Question 17

Circulating antibodies (IgG) react with a major and/or minor antigen of the hemidesmosomes anchoring basal cells to basement membrane

Answer 17

Bullous pemphigoid (IgG against hemi-desmosomes in basement membrane)

Question 18

Linear IgG and complement deposited around basement membrane!!

Answer 18

Bullous pemphigoid!!
Remember this is deeper = BM!!
(pemphigus = intraepidermal)

-send early lesions for biopsy, older ones may mimic pemphigus vulgaris

Question 19

Linear BM IgG

Answer 19

Bullous pemphigoid

Question 20

HLA-DQ2

Answer 20

Dermatitis herpetiformis

Question 21

Dermatitis herpetiformis associated with which HLA?

Answer 21

HLA-DQ2

Question 22

Papillary dermal microabscesses

Answer 22

Dermatitis herpetiformis

Question 23

Deposits of IgA in dermal papillae

Answer 23

Dermatitis herpetiformis

IgA antibodies target gliadin component of gluten but cross react with connective tissue matrix proteins

Immune complexes form in dermal papillae and activate complement and generate neutrophil chemotaxins.

Question 24

granular IgA

Answer 24

Dermatitis herpetiformis