Immunobullous Disorders Flashcards
What is attacked by Ig(?) antibodies in pemphigus vulgaris and what is its function?
IgG attacks desmoglein 3
Desmoglein 3 maintains desmosomal attachments
What is attacked by Ig(?) antibodies in bullous pemphigois and what is its function?
IgG attacks hemidesmosomes
Hemidesmosomes anchor basal cells to their basement membrane
What is the main feature of pemphigus vulgaris and why does it occur?
Acantholysis (loss of intercellular adhesion)
Occurs due to damage to desmoglein 3 which normally maintains intercellular adhesions
What is the main feature of bullous pemphigoid and why does it occur?
Tense blister formation
Occurs due to damage to hemidesmosomes which normally anchors basal cells to the basement membrane
What is the progression of the lesions in pemphigus vulgaris?
- Pruritic uricarial rash
- Blisters
- Erosions
Is Nikolsy’s sign positive or negative in pemphigus vulgaris?
Negative (top layers slip away when rubbed)
Is pemphigus vulgaris or bullous pemphigoid more likely to affect mucosal surfaces?
Pemphigus vulgaris
What can be seen histologically in pemphigus vulgaris?
Large fluid filled areas within the epidermis
What is seen on immunofluoresence in pemphigus vulgaris?
IgG forms honey comb arrangement (corresponds to desmoglein 3 on outer cell surface)
Is Nikolsy’s sign positive or negative in bullous pemphigoid?
Positive (top layers don’t rub away when rubbed)
What can be seen histologically in bullous pemphigoid?
Sub-epidermal blister and eosinophils
What is seen on immunofluoresence in bullous pemphigoid?
IgG forms linear arrangement (corresponds to hemidesmosomes on basement membrane
What is involved in the treatment of pemphigus vulgaris?
Emollients
Steroids
Good hygiene (prevent infection)
What is involved in the treatment of pemphigus vulgaris?
Emollients
Hygiene
Immunosuppression
Tetracycline antibiotics
What does the rash of dermatitis herpetiformis look like?
Mulitple small and intensely itchy lesions which are often excoriated
