Vesiculobullous Disease Flashcards
What are the two types of immunogenic mediated disease?
Cell mediated immunity
Antibody immediate immunity
What are some local oral diseases?
Aphthous ulcers
Lichen planus
OFG
All via cell mediated immunity
What are some systemic diseases that have local effects on the oral mucosa?
Pemphigoid
Pemphigus
Lupus
Sjogrens
Erythema Multiforme (type 3 hypersensitivity Rxn)
all via antibody mediated immunity
What is an antigen?
This is a substance/toxin that triggers the immune system and antibody formation as the body wants to eradicate it
What is a self antigen?
This is a normal protein or protein complex produced by the body that the immune system recognises as being harmful and creates an antibody to eradicate it and is the basis of how AI disease works
What is an antibody?
This is a protein made my B lymphocytes that bind to antigens to alter or eradicate them
What does an autoantibody attack on skin components do?
Causes loss cell adhesion and results in a split forming to which inflammatory exudate can pass and force apart different layers of skin resulting in blister or vesicle formation
What do hemidesmosomes to?
Attach epithelial cells to the basement membrane and each other
What do desmosomes do?
They attach epithelial cells to each other
What is the target antigen in many vesiculobullous diseases?
Desmoglein
What is erythema multiforme?
This is an immune mediated condition that can results in target skin lesions, lip crusting, genital lesions, oral ulcerations
more common in younger males
How does erythema multiforme occur?
This occurs when antigen antibody react to form a large complex in the circulation that eventually wedges in capillary and results in complement system being activated (triggers inflammation, phagocytes, enhances antibody activity) and as a result perivascular inflammation which results in blisters and ulceration
How long does EM last?
usually 2-3 weeks with 1-6 months of disease free period
it has acute onset
Where in the mouth can EM affect?
Anywhere including keratinised mucosa
What is the cause of the oral lesions in EM?
Often caused by herpes simplex virus reactivation which triggers an immune response leading to a type 3 hypersensitivity rxn
What can we do if pt has repeated oral mucosa lesions?
Can give aciclovir prophylactically - 400mg 2x day to suppress herpes simplex replication
How do we tx EM?
Hydration
Analgesia
High dose steroid (prednisolone up to 60mg) to suppress the immune system, and complement activation
prophylactic aciclovir if oral lesions
What is angina bulls haemorrhagica?
This is tight blood filled blisters in the oral mucosa that are benign and often causes by trauma during eating
Pt may present with painless blood filled blister or may have burst and present as ulceration that often is only mildly symptomatic for one day
Where is angina bullosa haemorrhagica often seen?
Buccal mucosa
Soft palate
What is the onset of ABH?
acute, rapid consent, often appears in few mins last one hour before bursting to form ulcer
Do we do any tests for ABH?
NO - ulcer comes back as non specific ulceration and negative test on immunofluorescence
What is the tx for ABH?
CHX - 0.2% 10ml 1min 2 x day
Diflamm - 0.15% mouth rinse that has anti-inflame and local analgesics
What is pemphigoid?
This is a condition where antibodies target hemidesmosomes and results in itchy raised rash which progresses to large blisters (more common in elderly pts)
How does pemphigoid occur?
This is where the antibody attacks hemidesmosomes resulting in separation of the epithelium at the basement membrane and fluid and inflammatory exudate fills the space between the epithelium and BM resulting in large blisters forming
sub-epithelial so more resistant to bursting and often pt will present with blisters intact
How will pt with pemphigoid present?
Blistering problem that lasts
in ruptured areas there is exposed CT and potential infection resin and fluid exudate
dehydration and infection risk
may be scarring if cicatritial pemphigoid - can cause narrowed oropharynx, scarred conjunctivae
Tyoes of pemphigoid?
Bullous pemphugoid = skin
Mucous membrane pemphigoid = eyes, genitals, mouth
Cicatritial pemphigoid = scarring type
How do we test for pemphigoid?
Gold standard is DIRECT IMUNOFLUORESCENCE - we take a peri-lesional sample (as if we take sample of lesion only we may not get good enough sample for testing)
Result will show LINEAR BASEMENT STAINING (as there is separation between the epithelium and CT but in perilesions sample we see staining along BM)
also presence of IgG and C3
How do we manage pemphigoid?
Steroid tx for immunosuppressant activity (prednisolone)
Immune modulation drugs such as aziothoprine
What is pemphigus?
This is an immune mediated antibody disease where antibody attacks the desmosomes resulting in painful life threatening blisters which burst leaving erosive area and mucosla surface loss
How does pemphigus occur?
It occurs due to antibody attacking desmosomes which attach epithelial cells together - the antibodies attack all around the cell results in epithelial cells losing adhesion and fluid exudate intra epithelially (less sub epithelial than pemphigoid so often blisters tend to burst)
Often only a few layers of cells around lesion as as the fluid exudate fills the space there is loss of epithelium - erosion of loss of mucosal coverage
If pt presents with intact blisters what do they not have?
thet dint have pemphigus - as blisters are fragile and burst easily and would present with erosion and loss of mucosal surface
Where is often affected in pemphigus?
Skin - 3 yrs after
mucosa - initially
How is pemphigus treated?
if no tx = fatal
high dose steroids
immune modulating drugs = aziothoprine
