Purpura, petechia, vasculitis Flashcards
def purpura
red purple color from blood extravasation into skin, can be palpable or flat
non blanching
two types of macular purpura
petechiae less than 3 mm
ecchymoses over 5 mm
contrast etiology of macular vs palpable purpura
macular- non inflammatory
palpable- vascular inflammation like vasculitis
diascopy
pressure w/ glass slide- blanching means erythema from vasodilation
retains red color is erythrocyte extravasation
causes of scurvy
insufficient vit C, increased need (from meds), increased loss (dialysis)
vit c needed for collagen, absence causes fragilit
scurvy pres
hemorrhagic gingivitis
perifollicular petechiae, keratotic plugging of hair follicles
petechiae and purpura w/ meningitis should raise concern for…
sepsis and DIC
neisseria meningtidis
G- diplococcus causes meningitis or sepsis
skin progression of RMSF
faint macules on wrists or ankles, becomes widespread and petechial on trunk, extremities, palms and soles
triad is fever, rash, hx of tickbite
hallmark lesion of leukoclastic vasculitis (small vessel vasculitis)
palpable purpura
contrast pres of small, medium, and large vessel vasculitis
small: palpable purpura
medium: subq nodules, purpura, fixed livedo reticularis
large: claudication, ulceration, necrosis
dx for palpable purpura
need skin biopsy to dx vasculitis- direct immunofluorescenc can show Ig, complement, fibrin deposits
common systemic vasculitis in kids
henoch schonlein purpura- purpura, arthritis, ab pain, kidney disease
peak time for HSP
winter- from preceding infection
dx feature of HSP
IgA deposition in vessel walls on biopsy
