Vesiculobulous eruptions Flashcards
Herpes histology
Necrosis of all epidermal cell types
multinucleated keratinocytes
dermal inflammation
Herpes clinical features
grouped vesicles on an erythematous base
Labialis usually HSV1, urogenital HSV2 but many overlap
Herpes Dx
based on morphology Tzank smear viral culture antibody testing skin biopsy
Varicella etiology
caused by Varicella-Zoster virus Hematogenous spread (Christmas tree distribution)
Varicella histology
necrosis of all epidermal cell types
multinucleated keratinocytes
dermal inflammation
Varicella clinical features
“dewdrop on a rose petal”
initial lesions are papules which become vesicles
eventually crust over, may heal with scarring
Herpes etiology
most adults have been exposed
virus persist in sensory ganglia
ppt by UV, menses, fever, URTI, immunodeficiency
Varicella Dx
viral culture
Tzank smear
skin biopsy
Herpes Zoster etiology
recurrent varicella-zoster virus
Herpes zoster histology
necrosis of all epidermal cell types
multinucleated keratinocytes
dermal inflammation
Herpes zoster clinical features
prodome of neuritic pain for days to weeks
acute vesicles, then crusted papules
distribution is unilateral and dermatomal
grouped vesicles on erythematous base
Herpes zoster Dx
viral culture
Tzank smear
skin biopsy
Nonbullous impetigo etiology
superficial infection of epidermis caused by GAS or staphy aureus
Nonbullous impetigo histology
neutrophils gathering beneath stratum corneum
Nonbullous impetigo clinical features
scalling
honey-crusted
non-bullous
Nonbullous impetigo dx
gram stain and culture
biopsy usually not required for dx
Bullous impetigo etiology
bacterial skin infection caused by staph aureus
Bullous impetigo histology
neutrophils gathering beneath stratum corneum
Bullous impetigo clinical features
vesicles and bullae
easily breakable
clear/slightly yellow fluid
shallow erosions form if bullae break
Bullous impetigo dx
gram stain and culture
biopsy usually not required for dx
Arthropod bites etiology
impossible to differentiate creature;
mites, ticks, spiders, centipedes, millipedes, mosquitos, black flies, sand flies, bedbugs, ants, bees, wasps, hornets, fleas
Arthropod bites clinical features
grouped papules or vesicles "breakfast-lunch-dinner" pattern pruritic/urticarial papules may be painful often only one person in each group is bitten
Bedbug etiology
red-brown, size of ladybug, not disease vectors
nocturnal
not confined to beds
bedbug clinical features
erythematous papules, vesicle,s nodules
bites on body and head and neck
