Oral blistering diseases Flashcards
What are the two types of immunogenic reactions?
- Cell mediated
- Antibody mediated
What type of hypersensitivity reaction happens in Erythema multiforme?
Type 3
What 3 diseases are related to cell mediated immunity?
- Apthous ulcers
- Lichen planus
- Orofacial granulomatosis
What 2 diseases is related to antibody mediated immunity?
- Pemphigus
- Pemphigoid
Why might oral disease and genital/skin are commonly linked?
Because they share many common antigens and epitopes
What are antigens?
- Immunogenic site within a protein
What is epitope?
- A specific site in an antigen that antibodies bind
Describe the immunological process in blistering disease?
Auto-antibody attack on skin component cause loss of cell to cell adhesion resulting in a split which is filled by inflammatory exudate forming a vesicle or blister
What is the difference between a vesicle and a blister?
- Vesicle 1-2mm
- Blisters are larger
What exactly do autoantibodies attack that causes loss of cell to cell adhesion?
Desmosomes and Hemidesmosomes
Briefly describe what is a desmosome and a hemidesmosome?
Desmosome - an attachment that bind cells together
Hemidesmosome - anchor cells to basement membrane
Describe how direct immunofluorescence work?
- by manufacturing an antibody with a flour-scene marker that binds to the primary antibody in the affected tissue , confirming its presence
How should the tissue for direct immunofloursence be transported?
Fresh , avoid formalin as it may cause the loss of binding sites
What is indirect fluorescence? and when to use it?
- it confirms the presence of antibodies circulating in the plasma that is not yet bound to the tissue
- not reliable as a diagnostic aid but can be used for monitoring
What is erythema multiforme?
A spectrum disorder of immunogenic related skin and mucosa ulceration and blistering
What do we call the severe form of erythema multiforme?
Stevens-johnson-syndrome
3 parts of the body other than the mouth that can be affected by stevens-johnson syndrome?
- Skin
- Eyes
- Pharynx /nose
3 contributing things to the development of erythema multiforme?
- drugs
- herpes simplex
- mycoplasma
Which 2 parts of the mouth do erythema multiforme commonly affect?
- Lip and anterior parts of the mouth
What 3 signs might be associated with erythema multiforme?
- Crops of ulcers in the mouth that heal within 2 weeks
- Dysphagia
- Dehydration
What is the emergency management of erythema multiforme?
- high dose systemic steroids (prednisolone)
- systemic aciclovir
What advice would you give to a patient with erthema multiforme?
- increase fluid intake
- analgesia
Incidence or erythema multiforme?
Young males
What is advised when if there is recurrent problems with erythema multiforme ?
- prophylactic acivlovir daily
- allergy testing
What is the most common oral blistering condition?
- Angina bullosa haemorrhagica which is a blistering disease affecting the mouth that presents as blood filled blisters that burst within an hour leaving a relatively painless vesicle
- Sudden onset
- intermittent
What are angina bullosa haemorrhagica commonly called?
blood blisters
What are the commonest sites for angina bullosa haemorrhagica ?
Buccal mucosa and soft palate
What are 2 triggers of ABH?
- Trauma
- Eating
When do ABH heal?
Heal within days without scarring
What advice would you give a patient with ABH?
Use chlorhexidine mouthwash and reassure patient that it is benign
What is pemphigoid?
An autoimmune blistering disease characterised by thick walled blisters which can be filled with blood or clear fluid affecting the full epidermis
What are the three forms of pemphigoid?
- Bullous pemphigoid - skin
- Mucous membrane pemphigoid - all mucous membranes
- Circatritial pemphigoid - mucosal with scarring
What is the histopathological feature important in diagnosing pemphigoid?
Sub epithelial split at the epithelial/connective tissue junction involving hemidesmosomes at basement membrane
Describe the immunofluorescence appearance in pemphigoid?
- Linear staining along the basement membrane
- C3 and IgG detected in this area
Other than C3 and IgG what other antibodies can be found in pemphigoid?
IgA - linear staining (linear IgA disease)
In what disease is there granular IgA and C3 staining?
Dermatitis herpetiformis
What symptom/sign of pemphigoid is seen in the eyes?
Symblepharon
How can pemphigoid be managed?
- steroids - PREDNISOLONE
- immune modulating drugs
What is the commonest form pemphigus?
Pemphigus vulgaris which is an autoimmune blistering disease characterised by clear blisters that burst and spread which can be related to genetic factors
What are two common histological signs of pemphigus?
- Suprabasal split
- Tzank cells
What pattern of immunofluorescence is seen in pemphigus?
Basket weave pattern C3 and IgG
Which to proteins are associated with pemphigus vulgaris?
Desmoglein 1 and 3
What two proteins are associated with pemphigoid ?
BP180 and BP230
