Immunobullous diseases Flashcards
Bullous Pemphigoid - what is it?
Chronic autoimmune bullous disorder
Bullous Pemphigoid - who does it commonly affect?
Elderly people
Affects men and women equally
Bullous Pemphigoid - pathogenesis
Subepidermal blister
Bullous pemphigoiD = split is DEEP through DE junction
Bullous Pemphigoid - morphology
Large tense bullae
Blisters burst to form erosion
May first present with itchy erythematous plaques/papules
Urticated skin lesions
Bullous Pemphigoid - clinical presentation
Itchy
Bullous Pemphigoid - histology
Epiermis floats off of basement membrane
Predominance of eosinophils
Bullous Pemphigoid - investigations
Immunofluorescence - IgG and C3 at basement membrane
Skin biopsy
Nikolsky sign = -ve
Bullous Pemphigoid - common affected areas
Trunk and limbs
Bullous Pemphigoid - management
High dose systemic corticosteroids
Topical steroids - in frail patients
Pemphigus - what is it?
Rare autoimmune condition
Pemphigus - who does it commonly affect?
Middle aged
Affects males and females equally
Pemphigus - pathogenesis
PemphiguS - split is more SUPERFICIAL i.e. going through the epidermis
Loss of integrity of epidermal cell adhesion
Pemphigus - morphology
Fragile fluid filled blisters
Blisters rupture to form shallow erosions
Can have mucosal involvement - in severe disease
Pemphigus - common areas affected
Head
Torso
Pemphigus - histology
Acantholysis (separation of epidermal cells)
Pemphigus - investigations
Skin biopsy
Immunofluorescence
Nikolsky sign = +ve (indicates plane of cleavage is within the epidermis)
Pemphigus - investigations
Skin biopsy
Immunofluorescence - IgG, desmoglian 3
Nikolsky sign = +ve (indicates plane of cleavage is within the epidermis)
Pemphigus - management
High dose oral steroids
Life-long treatment
Immunosuppressants - azathioprine
Epidermolysis bullosa - what is it?
Due to inherited skin abnormalities which result in skin fragility
Epidermolysis bullosa - who does it commonly affect?
Infants (at birth or shortly after)
Epidermolysis bullosa - 3 main types
Simplex
Junctional
Dystrophic
Epidermolysis bullosa - morphology
Large fluid filled blisters
Eventually digits are lost an it results in mitten fingers
Epidermolysis bullosa - clinical presentation
Extensive skin loss when baby is handled or moved
Epidermolysis bullosa - pathogenesis
Mutation in one of the DE junction proteins causes the epidermis and dermis to separate from each other
Epidermolysis bullosa - genetics
Haploinsufficiency
Dermatitis Herpetiformis - what is it?
Uncommon
Subepidermal blistering eruption
Dermatitis Herpetiformis - common associated disease?
Coeliac disease
Dermatitis Herpetiformis - which gene is it associated with?
HLA-DQ2
Dermatitis Herpetiformis - areas commonly affected
Buttocks
Elbows
Knees
