Vesiculobullous disorders Flashcards
What type of disorder is a vesiculo-bullous disorder?
chronic inflammatory disorders
they are unpleasant, chronic, sometimes life-threatening disorders
Mechanism
auto-antibodies target structural proteins of desmosome and hemi-desmosomal (adhesion molecules) plaques in skin and mucosa -> leading to formation of blisters: vesicles (small) or bullae (big)
Where are the blisters located?
either intra-epithelial (within structure of epithelium) or subepithelial (at junction of epithelium and connective tissue)
Clinical presentations (4)
erythema
blisters
erosions
ulcers
Clinical symptoms (3)
- pain at site
- dysphagia (if in oropharynx)
- foetor (unpleasant smell of the infection)
2 vesiculobullous disorders most commonly associated with oral disorders/presentations
pemphigus vulguris
mucous membrane pemphigoid (most common VB disorder)
Characteristic feature of mucous membrane pemphigoid following the process of erythema, ulceration, erosion etc?
scar formation
(can be in oesophagus, larynx, conjunctiva)
Oesophageal Strictures, Laryngeal Stenosis, Conjunctival Cicatrization
How severe are the skin effects of MMP?
mild (relative to other conditions like PV as it is a mucous membrane disorder)
Aetiopathogenesis of MMP.
What is the histopathological presentation?
- IgG and/or IgA auto-antobodies target hemi-desmosomes in epithelial basement membrane zone (EMBZ)
What is a subtype of MMP
Linear IgA disease (LAD)
What age is MMP most common in?
55-65
Describe clinical presentation of MMP
- thick-walled bullous lesion
- lasts several days
- irregular erosions/ulcers after bullae burst
- on NON-keratinised mucosa
- may be blood filled
- oral lesions usually heal without scarring
What associated condition may you see with MMP. Describe it (3)
desquamative gingivitis
erythematous and hyperaemic mucosa
small bullae formation
extends BEYOND marginal gingiva
How do you diagnose MMP?
- 2 x incisional biopsies for histopathology (standard saline) AND immunofluorescence (frozen) technique
-serum
What kind of incisional biopsy if you suspect MMP and why?
perilesional - take it of the mucosa surrounding the lesion
-not of the bullae/ulcer as you wont see the process of epithelial detachment
→ want to see the where epithalium detached from lamina propia
What does immunofluorescence do?
designed to identify and confirm the appearance seen in histopathology (can see light from fluorophore) Fluorescently-labelled Antibodies to identify bound Auto-Antibodies
- → see linear IgG along epithelial basement membrane zone (but rmb theres also IgA subtype)*
direct: biopsy sample
indirect: patients serum
What to do if see patient with MMP?
refer to specialist
Treatment for MMP (4)
topical corticosteroids
systemic corticosteroids
immunosuppressant therapy e.g. azathioprine, dapsone
good OHI
Why is Pemphigus Vulgaris potentially lethal?
blistering and ulcerations on skin - risk of:
- infection
- fluid and protein loss
- dysphagia
First sign of PV
oral lesions usually precede skin lesions
Describe PV general features
- rare
- chronic
- potentially lethal
- can be drug induced
Aetiopathogenesis of PV. Where does it occur?
IgG auto-antibody binding targeting Desmosomal proteins - interferes with cell adhesion
intra-epithelial (whereas MMP is subepithelial)
does have acantholysis (whereas MMP doesnt)
Clinical features of PV
- painful, fragile, fluid filled blisters
- both skin and oral mucosa but oral lesions precedes
- burst within a few hours, shallow ulcers and erosions lesion
(MMP is whole epithelium lining, these are just skin so burst easily)
- can be located on soft/hard palate, buccal mucosa, lips, gingiva (not just on non-keratinised mucosa unlike MMP)
- can be drug induced
Histopathology of MMP vs VB
MMP
- subepithelial bullae
- no acantholytic cells
- epithelium detaches from underlying lamina propia( Loss of Connection between Basal Epithelial Cells & Dermis)
VB
- intra-epithelial bullae (disintegration within epithelium)
- acantholytic cells (cells coming apart)
- leucocyte infiltration in lamina propia
