pemphigoid

Question 1

synchronous cancers

Answer 1

cancers which have arisen at the same time

Question 2

metachronous cancers

Answer 2

cancers which develop subsequent to original lesions but are part of the same field change

Question 3

toluidine blue

Answer 3

proposed method of oral cancer detection
dye applied to mucosa that stains particular markers within cells, good for showing change and dysplasia but also shows areas of trauma an inflammation

Question 4

velscope

Answer 4

proposed method of oral cancer detection
autofluorescence of tissues with blue light
loss of fluorescence equates to change but change is not necessarily cancer

Question 5

why do diseases affecting oral mucosa also often present on skin

Answer 5

embryologically they develop from the same origin

Question 6

antigen vs epitope

Answer 6

antigen - substance that illicits an immune response
epitope - area on antigen where antibody will bind

Question 7

desmoglein

Answer 7

protein that acts as an adhesion molecule to maintain tissue integrity, facilitate cell-cell communication and form junctions known as desmosomes

Question 8

name a target of many auto-antibodies in pemphigus

Answer 8

desmoglein

Question 9

direct immunofluorescence

Answer 9

assesses for antibodies already bound to tissues
uses lab manufactured second antibody which has fluorescence attached, this will bind to primary antibody already attached and fluorescence will highlight location

Question 10

indirect immunofluorescence

Answer 10

looks for circulating antibody not yet bound to tissue
not useful for diagnosis but can be good for monitoring disease activity

Question 11

brief description of erythema multiforme

Answer 11

immune mediated mucocutaneous condition

most common precipitator is HSV
generally self limiting , lasts around 3 weeks

Question 12

characteristic lesion of erythema multiforms

Answer 12

target lesion on skin

Question 13

angina bullosa haemorrhagica

Answer 13

‘tight blister blood filled’
Blood blisters in mouth most commonly on buccal mucosa or soft palate

Question 14

timeline of angina bullosa haemorrhagica blisters

Answer 14

Rapid onset, within a few minutes, last about an hour then burst - ulceration seen during recovery
relatively painless, discomfort comes from ulceration
heals with no scarring

Question 15

pemphigoid

Answer 15

sub epithelial antibody attack
antibodies cause separation of epithelium from connective tissue at basement membrane, space filled with fluid and inflammatory exudate creating blister

Question 16

describe a pemphigoid blister

Answer 16

fluid and inflammatory exudate fill space between connective tissue and epithelium so full thickness layer of epithelium above blister meaning they can persist for some time and intact bullae are often seen
Can be clear or blood filled - sometimes rbcs can leak into blister due to immunological damage

Question 17

name the 3 different forms of pemphigoid

Answer 17

bullous pemphigoid - skin lesions
mucous membrane pemphigoid - mucous membranes (oral, eye, genital)
Cicatritial pemphigoid - mucous membranes with scarring (subdivision of mucous membrane)

Question 18

what type of biopsy is required when investigating pemphigoid and pemphigus

Answer 18

peri-lesional
lesion itself may have no epidermis present due to blister making diagnosis difficult

Question 19

what do antibodies attack in pemphigoid

Answer 19

hemidesmosomes
results in loss of attachment between epidermis and connective tissue

Question 20

what is the most useful diagnostic test for pemphigoid and what will it show

Answer 20

direct immunofluorescence
will show linear basement membrane staining
fluorescent tag binds to antibody bound to antigen on basement membrane that has not yet separated

Question 21

what are the most common antibodies implicated in pemphigoid

Answer 21

C3 and IgG