vestibulobullous dz Flashcards
Hemidesmosomes function
hold basal cells to dermis (basement membrane zone)
Desmosomes function
hold individual keratinocytes to each other (intracellular bridges)
cause of pemphigus vulgaris
auto-antibody to intra-cellular bridges (desmoglein 1, 3) leading to kertinocytes falling apart
FLACCID bullae & erosions with PAINFUL ORAL erosions
pemiphigus vulgaris– autoimmune
what happens when you do the nikolsky’s test on pemphigus vulgaris
bullae extends with lateral tension (positive)
what happens if pemphigus is not treated
fluid loss + infection = high mortality
direct immunofluorescence with pemphigus vulgaris shows..
chicken-wire deposition of antibodies between keratinocytes
what causes bullous pemphigoid
auto-antibody to basement membrane; inflammatory cell recruitment leads to blisters
TENSE, itchy bullae with widespread distribution that could’ve started out as urticarial plaques
bullous pemphigoid
how is bullous pemphigoid diagnosed
biopsy of perilesional skin (autoantibodies destroyed in blister formation)
direct immunofluorescence detects auto-antibodies in basement membrane
age & mortality rate of pemphigus vs bullous pemphigoid
age: pemphigus has broad range onset while bullous pemphigoid is 60+ & increases w/ age
mortality rate: bullous has very low rate
how is bullous pemphigoid treated (2)
high potency topical steroids like clobetasol
systemic agents
drug eruption causing widespread epidermal cell necrosis with sheets of sloughed skin
SJS or TEN
key features of SJS/TEN (3)
severe skin PAIN, dusky red macules
bullae and sheets of denuded skin (+ Nikolsky’s sign)
Mucosal erosions
how fast can you see SJS/TEN reaction after starting new drug
7-21 days
how is SJS/TEN managed?
refer to burn center asap!!
type 4 hypersentivity; acute blistering rxn characterized by TARGETOID lesions +/- mucosal ulceration following infection (HSV or mycoplasma) or drug; in 20-40yo
erythema multiforme
cause of erythema multiforme
immune rxn to infection
EM minor vs major
minor: typical targets, little to no mucosal involved
major: atypical or large targets, severe mucosal erosions in 1 or 2 mucosal surfaces
when someone has erythema multiforme, what can you expect to happen shortly after?
herpes outbreak!! it precedes herpes outbreak in 80% of patients
location of erythema multiform
hands & forearms, palms neck & face –> inward spreading to trunk
concentric zones of color change with central blister formation &/or crust
can erythema multiform be itchy or painful?
frequently itchy, sometimes painful
how is erythema multiform tx (4)
lesions resolve in 2 wks w/o scarring
tx underlying infxn (HSV, mycoplasma)
supportive care for lesions
if recurrent– suppressive antiviral
