19.2: Blistering Dermatoses Flashcards
What is the pathophysiology of pemphigus vulgaris?
-Autoimmune destruction of desmosomes
What type of immunoglobin is involved in pemphigus vulgaris? What protein is it directed against?
IgG against desmoglein
What is the IF staining pattern associated with pemphigus vulgaris?
IgG surrounding keratinocytes in a “fish net” pattern
Fishnet pattern on IF stain of epidermis = ?
Pemphigus vulgaris
What is the protein that holds together epidermal cells?
Desmosomes, formed of desmoglein
What is the protein that holds the epidermis to the BM?
Hemidesmosomes
In what layer of the skin do blisters from pemphigus vulgaris form?
Epidermis–specifically the stratum spinosum detaches
Why is it that the blisters with pemphigus vulgaris rupture easily?
Only a partial, thin layer of epidermis comprises the blister
Which involves the skin and oral mucosa: pemphigus vulgaris or bullous pemphigoid
Pemphigus vulgaris
What is the pathophysiology of bullous pemphigoid?
Autoimmune attack against the hemidesmosomes
What is the antibody class that is implicated with bullous pemphigoid? What is it directed against?
IgG against the BM
How does bullous pemphigoid present?
Tense subepidermal blisters of the skin with oral mucosa sparing
Which has tense bullae, and which has flaccid bullae: bullous pemphigoid; pemphigus vulgaris
Tense = bullous pemphigoid
Flaccid = Pemphigus vulgaris
In what skin layer do the blisters with bullous pemphigoid form?
between the dermis and the epidermis
What are the IF findings of bullous pemphigoid?
Linear IgG antibodies along the BM
Why are the bullae tense and hard to rupture with bullous pemphigoid?
Whole epidermis is present in the wall of the blister
What is dermatitis herpetiformis?
-Autoimmune deposition of IgA at the tips of the dermal papillae (“just the tips”)
What type of immunoglobin is implicated in the pathogenesis of dermatitis herpetiformis? What are these directed against?
- IgA
- Ab against gluten
What GI disease is associated with dermatitis herpetiformis?
Celiac Sprue
What is the treatment for dermatitis herpetiformis?
Gluten control
What is erythema multiforme, and what are the skin characteristic of this disease?
-HSR with targetoid rash and bullae
targetoid rash and bullae = ?
Erythema multiforme
What infectious disease is associated with erythema multiforme?
HSV
Erythema multiforme with oral mucosal involvement and fever is what?
Steven-Johnson’s syndrome
What is toxic epidermal necrolysis?
Severe form of SJS
What, generally, is SJS?
Diffuse sloughing of skin resembling a large burn
What usually causes SJS?
Adverse drug reaction
What is the antiepileptic agent that classically is associated with SJS?
Lamotrigine
