5. Vesiculobullous & Immune Disease Flashcards by Abbie Mitchell

Define vesicle.

<5-10mm in size.

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Define bullae.

> 10mm in size.

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What type of hypersensitivity reaction is erythema multiforme ?

Type 3

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SPECIAL INVESTIGATIONS

What is immunofluorescence ?

Permits visualisation of components in tissue/cell type.
Identifies presence of antibodies.

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When is direct immunofluorescence preferred ?

In diagnosis of disease.

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When is indirect immunofluorescence preferred ?

Monitoring disease activity and determining treatment need.

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SPECIAL INVESTIGATIONS

What is direct immunofluorescence ?

Where antibody is bound to tissue.

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SPECIAL INVESTIGATIONS

What is indirect immunofluorescence ?

Circulating antibody not yet bound to tissue (detected by immunofluorescence from plasma sample).

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ERYTHEMA MULTIFORME

Does it affect males or females more ?

Males (young males late teens/early 20s).

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ERYTHEMA MULTIFORME

What are the aetiological factors ?

Reactivation of herpes simplex virus.

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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.

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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.

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ERYTHEMA MULTIFORME

What is the name for erythema multiforme in its extreme form (multisystem involvement) ?

Stevens Johnson syndrome.

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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.

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ERYTHEMA MULTIFORME

What is erythema multiforme ?

Spectrum disorder of immunogenic related skin and mucosal ulceration (with variable orofacial involvement).

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ANGINA BULLOUSA HAEMORRHAGICA

What is angina bullosa haemorrhagica (ABH) ?

Formation of tight, blood filled blister on oral mucosa.

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ANGINA BULLOUSA HAEMORRHAGICA

Where in the mouth does ABH most commonly affect ?

Buccal mucosa, soft palate.

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What is the most common oral blistering condition ?

ABH

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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.