Immunobullous disorders Flashcards Preview

1. Dermatology > Immunobullous disorders > Flashcards

Flashcards in Immunobullous disorders Deck (13)
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1
Q

What is Pemphigus?

A

An autoimmune condition characterised by fluid filled blisters on skin (and eyes and genitals) can be fatal if extensive mucosal involvement
high mortality rate

2
Q

What is the pathophysiology of pemphigus?

A

IgG autoantibodies are made against desmoglen 3 which maintains desmosomal attatchments.
Therefore immune complexes form on cell surface and complement is activated and proteases are released
This disrupts desmosomes and leads to acantholysis

3
Q

What is nickolsklys sign?

A

when the skin is rubbed it falls away - acantholysis

4
Q

Is pemphigus nickolskly sign positive or negative?

A

positive

5
Q

How is pemphigus investigated?

A

skin biopsy with immunofloresence or indirect immunofloresence

6
Q

How is pemphigus treated?

A

steroids - either topical or systemic

7
Q

What is bullus pemphigoid?

A

subepidermal blister (in dermal-epidermal junction)

8
Q

What is the pathophysiology of bullus pemphigoid?

A

circulating IgG antibodies react with antigens of hemidesmosomes which anchor basal cells to the basement membrane
This causes complement activation and tissue damage

9
Q

How does bullus pemphigoid present?

A

itchy erythemous plaques and papules
mainly affects elderly
nickolsky sign negative

10
Q

How is bullus pemphigoid treated?

A

tetracycline

11
Q

What is dermatitis herpetiformis?

A

intensly itchy lesions on elbows, knees and buttocks

12
Q

What is the hallmark of dermatitis herpetiformis?

A

papillary dermal microabscesses

13
Q

What is dermatitis herpetiformis associated with?

A

coeliac disease and HLA-DQ2 haplotype
antibodies target gliadin component and cross react with connective tissue matrix proteins
immune complexes form in dermal papillae and generate neutrophil chemotaxis