Blistering Dermatoses Flashcards
Pathology of Pemphigus vulgaris, type of hypersenistivity reaction?
Autoimmune destruction of desmosomes between keratinocytes, IgG Ab against desmoglein (type II hypersensitivity
Pemphigus vulgaris histological presentation
Acantholysis of stratum spinosum keratinocytes from stratum basalis resulting in basal layer cells attached to basement membrane with “tombstone appearance”.
What is Nikolsy sign?
Easy rupture of blisters in pemphigus vulgaris leading to shallow erosions with dried crusts
What are the findings for Pemphigus vulgaris on immunofluorescence?
Highlights IgG surrounding keratinocytes in “fishnet” pattern
What is Bullous Pemphigoid?
Autoimmune destruction of hemidesmosomes b/w basal cells and underlying basement membrane due to IgG Abs (hemidesmosome components BP180)
Bullous Pemphigoid presentation
Generally elderly with blisters on skin, oral mucosa is spared
What is the cause of the clinical presentation in Bullous Pemphigoid?
The blisters do not easily rupture because the entire dermis is involved
Histological findings of Bullous Pemphigoid?
Immunofluorescence highlights IgG along basement membrane (linear pattern)
What is Dermatitis Herpetiformis?
Autoimmune deposition of IgA at tips of dermal papillae
Clinical presentation of Dermatitis Herpetiformis?
Pruritic vesicles and bullae that are grouped
What disease is Dermatitis Herpetiformis associated with?
Celical disease - resolves with gluten-free diet
What is Erythema Multiforme?
Hypersensitivity rxn characterized by targetoid rash (central epidermal necrosis surrounded by erythema) and bullae
What conditions are associated with Erythema Multiforme?
HSV, Mycoplasma infection, Drugs (penicillin/sulfonamides), Autoimmune disease (SLE), malignancy
What is Stevens-Johnson Syndrome?
Erythema Multiforme with oral mucosa/lip involvement and fever
What is Toxic Epidermal Necrolysis?
Severe form of SJS characterized by diffuse sloughing of skin, resembling large burn; Frequently due to adverse drug reaction
