Skin Infections Flashcards
morphology of varicella
vesicle, pustule with secondary morphology of crusting and erosion
acute viral illness secondary to primary exposure to human herpes virus 3
how does varicella present?
fever, malaise and myalgia, then eruption begins on face and scalp within 24-48hr as crops of erythematous papules w/ central vesiculation
older lesions develop into pustules then crust to heal in 7-10 days
virus reamins in dormant in nerve ganglia for reactivation
what results as a reactivation of dormant varicella?
herpes zoster
pattern of skin dermatomes
what sequelae of varicella requires opthalmologic consult?
facial involvement of 1st branch of trigeminal nerve
evaluate for corneal involvement
what is the morphology of HSV lesions?
grouped vesicles evolving into pustules
Tx of HSV
antivirals PO
acyclovir, famciclovir, valacyclovir
what is this a presentation of?
HSV on finger; appear deeper due to increased thickness of stratum corneum on palmar aspect of finger
what is this a presentation of?
erythema multiforme (EM)
papules, vesicle
target lesions
precipitated by infection
minor and major; minor has no mucosal involvement
what is the presentation of scabies?
pruitic dermatitis
caused by scabiel var. hominis
burrow sign (wavy, thread-like, grayish-white)
what is the timeline of scabies infestation?
30-day life cycle of mites
incubation period before symptoms develop can range from days to months
2-6 weeks before sensitization
Tx for scabies
two topical treatments 1 wk apart
applied overnight from head to toe
permethrin cream
for children under 2 and pregnant women, sulfur in petrolatum
what precautions should you take in a household with scabies outbreak?
no need to treat pets
all family members and close contacts
dx of head lice
presence of 0.8mm eggs (nits) attached to scalp hairs
Tx for head lice
topical pediculoside
2 applications, 1 week apart
what is this a presentation of?
malassezia furfur causing tinea versicolor
well demarcated brown scaling patches that cause temporary hypopigmentation
morphology of thrush
primary: erosion
secondary: macerated white scale
what is this a presentation of?
candida intertrigo
primary morphology: patch, pustules, papules
secondary morphology: erosions, scale
diaper rash is form of intertrigo (superinfected with candida)
what is this a presentation of?
dermatophytoses
three genera: microsporum, trichophyton, epidermophyton
what is the morphology for all forms of tinea?
primary: annular plaque, patch, vesicle
secondary: scale, fissure
what is this a presentation of?
tinea pedis
this pattern of thicken stratum corneum is called
moccasin pattern
what is this a presentation of?
tinea cruris (jock itch)
what is this a presentation of?
tinea unguis
what is this a presentation of?
molluscum contagiosum
morphology: umbilicated papule, pearly, waxy papules
resolve spontaneously
Tx with curettage, manual expression, cryotherapy
what is this a presentation of?
HPV wart
papule, plaque, verrucous
hyperkeratotic, exophytic, dome-shaped
punctuate black dots (thrombosed capillaries)
what is this a presentation of?
flat warts
Tx for HPV warts
cryotherapy
what is this a presentation of?
impetiginization
excoriation of antecubital fossae
honey colored, sticky crusts
what is this a presentation of?
folliculitis
pustule
erythematous rim
shaving exacerbates folliculitis
what is this a presentation of?
furuncle/carbuncle (contiguous collection of boils)
boils
collection of pus walled off from surrounding tissues
Tx with PO cephalosporin
what is this a presentation of?
staphylococcal scalded skin syndrome
patch, dcaling or desquamation is secondary morphology
primarily disease of infants and young children
flexual areas
what is TTS caused by
S. aureus exotoxin
sudden onset of high fever
diffuse erythema, scarlatiniform exanthem
Tx with beta-lactamase resistant Abx
what is this a presentation of?
erysipelas
superficial variant of cellulitis
caused by strep
10-14 day penicillin
what is this a presentation of?
cellulitis
rubor (erythema)
calor (warmth)
dolor (pain)
tumour (swelling)
Tx for cellulitis
10-day course of Abx (cephalexin, clindamycin, dicloxacillin)
what is this a presentation of?
necrotizing fasciitis
rapidly progressive necrosis
severe pain out of proportion ot skin findings
does not respond to Abx
