5. Vesiculobullous & Immune Disease Flashcards
Define vesicle.
<5-10mm in size.
Define bullae.
> 10mm in size.
What type of hypersensitivity reaction is erythema multiforme ?
Type 3
SPECIAL INVESTIGATIONS
What is immunofluorescence ?
- Permits visualisation of components in tissue/cell type.
- Identifies presence of antibodies.
SPECIAL INVESTIGATIONS
When is direct immunofluorescence preferred ?
In diagnosis of disease.
SPECIAL INVESTIGATIONS
When is indirect immunofluorescence preferred ?
Monitoring disease activity and determining treatment need.
SPECIAL INVESTIGATIONS
What is direct immunofluorescence ?
Where antibody is bound to tissue.
SPECIAL INVESTIGATIONS
What is indirect immunofluorescence ?
Circulating antibody not yet bound to tissue (detected by immunofluorescence from plasma sample).
ERYTHEMA MULTIFORME
Does it affect males or females more ?
Males (young males late teens/early 20s).
ERYTHEMA MULTIFORME
What are the aetiological factors ?
Reactivation of herpes simplex virus.
ERYTHEMA MULTIFORME
Symptoms/signs ?
Target like skin lesions.
Crusting of the lips.
Ulceration of the mouth affecting keratinised and non-keratinised tissue.
Unable to eat/drink - due to pain.
Looks similar to primary herpetic stomatitis.
ERYTHEMA MULTIFORME
Explain how the type 3 hypersensitivity reaction occurs ?
- Antigen (present in body before) targeted by antibodies causing prompt immune response.
- Antigen-antibody complex formed - large and cannot pass through capillaries.
- Becomes lodged in capillaries when passing through tissues.
- Activates BVs causing perivascular inflammatory response.
ERYTHEMA MULTIFORME
What is the name for erythema multiforme in its extreme form (multisystem involvement) ?
Stevens Johnson syndrome.
ERYTHEMA MULTIFORME
You work in secondary care setting and a patient presents with EM - what treatment can you offer ?
High dose prednisolone - suppress immune reaction - up to 60mg/day.
Acyclovir prophylaxis - prevent reactivation of virus - 400mg 2x daily.
Encourage hydration - maybe admission for IV ?
Encourage analgesia.
ERYTHEMA MULTIFORME
What is erythema multiforme ?
Spectrum disorder of immunogenic related skin and mucosal ulceration (with variable orofacial involvement).
ANGINA BULLOUSA HAEMORRHAGICA
What is angina bullosa haemorrhagica (ABH) ?
Formation of tight, blood filled blister on oral mucosa.
ANGINA BULLOUSA HAEMORRHAGICA
Where in the mouth does ABH most commonly affect ?
Buccal mucosa, soft palate.
What is the most common oral blistering condition ?
ABH
ANGINA BULLOUSA HAEMORRHAGICA
Signs/symptoms ?
Blood filled blisters with rapid onset (in minutes) and last around an hour and then burst.
Painless.
Heal with no scarring.
ABH - aetiology ?
No obvious etiological factor.
Minor trauma ?
Inhalers ?
ANGINA BULLOUSA HAEMORRHAGICA
What is found on biopsy ?
Non-specific ulceration.
DIF, IIF negative.
No platelet/coagulation defect.
ANGINA BULLOUSA HAEMORRHAGICA
What are the only treatment options for angina bullosa haemorrhagica ?
Symptomatic relief - chlorhexidine or diflam spray.
Reassure patient that it is benign.
PEMPHIGOID/PEMPHIGUS
What is pemphigoid ?
Immune mediated antibody-directed disease - “sub-epithelial antibody attack” - causing antibody production against desmosomes (which join basement membrane and CT).
PEMPHIGOID/PEMPHIGUS
Explain how pemphigoid results in blistering ?
Antibodies cause separation of epithelium at basement membrane from CT.
Inflammatory exudate fills space between epidermis and CT.
Blisters appear.
PEMPHIGOID/PEMPHIGUS
Define the type of blistering found in pemphigoid.
Thick walled blisters (full epidermis).
Clear or red.
Persist for long time.
PEMPHIGOID/PEMPHIGUS
What are three different types/presentations of pemphigoid ?
Bullous pemphigoid (skin).
Mucous membrane pemphigoid (eyes, genitals, mouth).
Cicatritial pemphigoid (leaves scarring).
PEMPHIGOID/PEMPHIGUS
Pemphigoid - what might be seen histopathologically ?
- Sub-epithelial split between epithelium and CT junction.
- Hemi-desmosomes involved at basement membrane.
- Superficial perivascular inflammatory infiltrate.
- Inflammatory exudate containing fibrin, erythrocytes and inflammatory cells within cleft.
PEMPHIGOID/PEMPHIGUS
Pemphigoid - what is the most useful diagnostic test ?
Immunofluorescence.
PEMPHIGOID/PEMPHIGUS
Pemphigoid - what might be seen on immunofluorescence ?
Linear staining along basement membrane.
C3 and IgG detected in standard pemphigoid (IgA occasionally - will have patchy appearance).
PEMPHIGOID/PEMPHIGUS
In a secondary care setting, how should pemphigoid be managed ?
Topical steroids - tacrolimus.
Systemic steroids - prednisolone.
Immune modulating drugs - azathioprine, mycophenolate, dapsone.
PEMPHIGOID/PEMPHIGUS
Define pemphigus.
Immune mediated antibody-directed disease - where antibody is produced against desmosomes which join epithelial cells together.
Causes epithelial cells to lose adhesion and intraepithelial bullae to form.
PEMPHIGOID/PEMPHIGUS
How does pemphigus present ?
Thinning of epithelium progressing to loss of epithelium (rare to see intact bullae).
Therefore - mucosal erosion and mucosal surface loss.
PEMPHIGOID/PEMPHIGUS
What is the difference between pemphigus vs. pemphigoid ?
Pemphigoid - intact bullae will be visible.
Pemphigus - erosive presentation.
PEMPHIGOID/PEMPHIGUS
What is the main concern associated with both pemphigoid and pemphigus ?
Fluid loss and infection risk.
PEMPHIGOID/PEMPHIGUS
What is the most common type of pemphigus ?
Pemphigus vulgaris.
PEMPHIGOID/PEMPHIGUS
What age bracket does pemphigus affect most commonly ?
50+
PEMPHIGOID/PEMPHIGUS
Does pemphigus affect males or females more commonly ?
Females.
PEMPHIGOID/PEMPHIGUS
What particular genetic and racial group has a predisposition to developing pemphigus ?
Ashkenazi jews.
PEMPHIGOID/PEMPHIGUS
What sites does pemphigus affect ?
Oral (usually first) then skin (both will eventually become involved).
PEMPHIGOID/PEMPHIGUS
Pemphigus - around what time does skin involvement occur post-oral involvement ?
3 years
PEMPHIGOID/PEMPHIGUS
Pemphigus - what will be seen histopathologically ?
Supra-basal split - occurring above basement membrane.
Tzank cells.
PEMPHIGOID/PEMPHIGUS
Pemphigus - what will be seen on immunofluorescence ?
Basket-weave pattern.
C3 and IgG.
PEMPHIGOID/PEMPHIGUS
What type of biopsy should be taken for pemphigus and pemphigoid ?
Perilesional biopsy.
PEMPHIGOID/PEMPHIGUS
What are the signs/symptoms of pemphigus ?
Erosive lesions.
Appears like desquamative gingivitis.
Affects any part of oral mucosa.
Rarely see intact bullae.
PEMPHIGOID/PEMPHIGUS
You are treating a patient with pemphigus vulgaris in secondary care setting - what treatment can you provide ?
High dose systemic steroids - prednisolone.
Immunosuppressants - azathioprine and mycophenolate.
