Bullous Disorders Flashcards
describeb what bullous or immunobullous disorders are
autoimmune disorders where damage to adhesion mechanisms in skin result in blistering in various levels of skin
(blisters are primary feature)
what is the difference between bullous pemphigoid and pemphigus vulgaris
pemphigoid = split is deeper, through DEJ pemphigus = split more superficial, intra-epidermal
what are the 3 main types of bullous disorder
bullous pemphigoid, pemphigus vulgaris, dermatitis herpetiformis
what sites does bullous pemphigoid usually affect
localised to one area, or widespread on trunk and proximal limbs
what clinical features are seen with bullous pemphigoid
large tense bullae on normal erythematous skin, non scarring, itchy erythematous plaques and papules may be PC
what is the Nikolsky’s Sign
when the top layers of the skin slip away from the lower layers when slightly rubbed, indicates plane of cleavage within the epidermis
in what bullous disease is Nikolsky’s sign negative and what one is it positive
negative = bullous pemphigoid positive = pemphigus vulgaris
what sites does pemphigus vulgaris usually affect
scalp, face, axillae, groins
what clinical features are seen in pemphigus vulgaris
fluid filled flaccid vesicles/bullae(thin roofed), mucosal involvement(eyes, genitals), urticated itchy plaques in early disease
what happens when lesions in bullous pemphigoid and in pemphigus vulgaris rupture
pemphigoid = leave erosions pemphigus = leave raw areas
describe the pathogenesis of pemphigoid vulgaris
IgG antibodies made agaisnt desmoglein 3, which maintains desmosomal attachments, complement activation disrupts desmosomes and end result is acanthylosis
describe the pathogenesis of bullous pemphigoid
circulating IgG antibodies react with hemidesmosomes anchoring basal cells to basement membrane, results in local complement activation and tissue damage
what other disease is dermatitis herpetiformis associated with
coeliac disease
what sites are usually affected by dermatitis herpetiformis
scalp, shoulders, elbows, knees and buttocks
describe the lesions in dermatitis herpetiformis and what is left when removed
intensely itchy, symmetrical, leave erosions when scratched off
