Pathology of Rashes

Question 1

What is hyerkeratosis?

Answer 1

increased thickness of keratin layer

Question 2

What is parakeratosis?

Answer 2

persistence of nuclei in the keratin layer

Question 3

What is acanthosis?

Answer 3

increased thickness of epithlieum

Question 4

What is papillomatosis?

Answer 4

Irregular eptihelial thickening

Question 5

What is spongiosis?

Answer 5

oedema fluid between squames increases prominence of intercellular prickles
-in severe case vesicles filled by oedema fluid develop

Question 6

4 main reaction patterns?

Answer 6

• spongiotic-intraepidermal oedema
• psoriasiform-elongation
• lichenoid-basal layer damage
• vesiculobullous-blistering

Question 7

What type of reaction pattern is eczema?

Answer 7

spongiotic-intraepidermal oedema

Question 8

What type of reaction pattern is psoriasis?

Answer 8

psoriasiform-elongation of the rete ridges

Question 9

What type of reaction is lichen planus and lupus?

Answer 9

lichenoid-basal layer damage

Question 10

What type of reaction is pemphigoid, pemphigus and dermatitis herpetiformis?

Answer 10

vesiculobullous-blistering

Question 11

what is the basic pathogenesis of psoriasis?

Answer 11

epidermal hyperplasia leading to increased epidermal turnover

Question 12

What gene type is psoriasis linked to sometimes?

Answer 12

associated specific HLA types

Question 13

What do lichenoid disorders look like?

Answer 13

itchy flat topped violaceous papules (violet)

Question 14

Lichen planus histology?

Answer 14

• irregular sawtooth acanthosis
• hypergranulosis + orthohyperkeratosis
• bad-like upper dermal infiltrate of lymphocytes
• basal damage with formation of cytoid bodies

Question 15

range of lichenoid disorders?

Answer 15

• lichen planus

- vacuolar interface change

Question 16

pemphigus

Answer 16

autoimmune bullous disease

Question 17

basic pathology of pemphigus

Answer 17

loss of integrity of epidermal cell adhesion i.e. epidermal cells float apart

Question 18

most common pemphigus?

Answer 18

pemphigus vulgaris

Question 19

Pemphigus vulgaris pathology?

Answer 19

-IgG auto-antibodies made against desmoglein 3 desmoglein 3 maintains demosomal attachments, immune complexes form on cell surface, complement activation & protease realease -> acantholysis

Question 20

What is acantholysis?

Answer 20

lysis of intercellular adhesion sites

Question 21

What body parts does pemphigus vulgaris usually involve?

Answer 21

• scalp
• face
• axillae
• groin
• trunk
• may effect mucosa e.g. mouth + resp.tract

Question 22

bullous pemphigoid where is blister?

Answer 22

subepidermal blister

-no evidence of acantholysis

Question 23

What do IgG antibodies react with in bullous pemphigoid?

Answer 23

antigen of hemidesmosomes anchoring basal cells to basement membrane

Question 24

Dermatitis herpetiformis what is it and what does it tend to be associated with?

Answer 24

autoimmune bullous disease associated with coeliac disease

Question 25

What antibody associated with dermatitis herpetiformis?

Answer 25

IgA

Question 26

Acne common places

Answer 26

face, upper back, anterior chest

Question 27

What are 4 triggers of rosacea?

Answer 27

• sunlight
• alcohol
• spicy foods
• stress

Question 28

What is link with rosacea and demodex mites?

Answer 28

sometimes mites get like stuck in the hair follicles and get caught up in the inflammatory process