Vesiculobullous lesions 1 Flashcards
(31 cards)
What are the immune mediated diseases with local effects on the mouth?
Aphthous ulcers
LP
OFG
What are the systemic immune mediated diseases which can also appear in the mouth?
Erythema Multiforme
Pemphigus
Pemphigoid
Lupus erythematosis
Systemic Sclerosis
Sjogren’s Syndrome
What type of hypersensitivity reaction is associated with erythema multiforme?
Type 3- related to antigen-antibody complexes
What immunogenic oral diseases are cell mediated?
Aphthous ulcers
Lichen Planus
Orofacial Granulomatosis
What immunogenic oral diseases are antibody mediated?
Pemphigus
Pemphigoid
Why are skin and oral immunological diseases related?
Often affects both due to common embryological origin
What is the difference between an antigen and an epitope?
Antigens- big immunogenic sites within protein
Epitope is the small part in sequence of protein which antibody binds to
-> Binding at these can affect conformation of protein
How does antibody binding to different epitopes affect disease course in Epidermolysis Bullosa?
Depending on epitope it can be mild or lethal form
How does damage occur in immunological skin diseases?
Auto-antibody attack on skin components (hemi-/desmosomes) causing loss of cell-cell adhesion
‘Split’ forms in skin
-> Fills with inflammatory exudate (forces apart layers)
-> Forms vesicle/blister
Which protein is targeted within desmosomes in immunobullous diseases?
Desmoglein
What is the difference between a vesicle and a blister?
Vesicle- 1-2mm
Blister- larger
How does direct immunofluorescence used to identify antibodies causing immunological conditions?
Secondary antibody with fluorescein binds to the primary antibody which is bound in the tissue
-> can be seen under fluorescent light
What are the requirements for DIF?
Sample must not be put into formalin containing transport medium as it causes loss of binding sites
Must be transported fresh and processed quickly
When is indirect immunofluorescence used?
When identifying a circulating antibody which is not bound in tissue
-> done using plasma samples
Less reliable for diagnosis but good for monitoring disease
Which disease is indirect immunofluorescence useful for?
Pemphigus- as antibody levels direct treatment need
What is erythema multiforme?
Spectrum disorder of Immunogenic related skin and mucosa ulceration
-> Variable orofacial involvement
What causes Erythema multiforme to occur?
Antigen presents which is targeted by antibody (antigen is usually one that has been met before and prompt immune response follows- antibodies produced by memory B cells)
Antigen and antibody combine to form complexes in circulation but cannot pass through capillaries, it can become wedged in tissue and results in activation of complement within BV causing perivascular inflammatory response (If significant- blistering and ulceration of tissue presents)
How does EM present in skin and mucosa?
Skin- target lesion/crusting lesions
Mucosa- ulcers
-> present similar to primary herpetic gingivostomatitis (can affect keratinised tissue)
Lesions tend to last for 2-3 weeks, there may be months between episodes or they can develop very quickly
What are the causes of EM?
Drugs
HSV reactivation triggering T3 rxn
Mycoplasma- infective agent
What areas can EM affect?
Mouth
Skin
Eyes- conjuctivae
Genitals
If multi-system and severe- it is known as Steven Johnson Disease
How is oral lesions in EM managed?
Drugs
-> systemic steroids – up to 60 mg/day (a high dose)
-> systemic aciclovir
Encourage fluid intake- May require admission for IV fluid if unable to drink due to discomfort
Encourage analgesia
How is recurrent EM managed?
Consider prophylactic aciclovir daily
Allergy test – a wide variety of environmental triggers
What is the dose of prophylactic aciclovir for EM?
400mg x 2 daily
-> helps supress virus replication and prevent emergence of EM and production of antibodies/immune complexes
What is angina bullosa haemorrhagica?
Angina- tight, Bullosa- blister, haemorrhagic- blood filled
-> painless blood blisters which occur in the mouth
