skin infections and infestations basics Flashcards
things caused by staphylococcus aureus
impetigo folliculitis cellulitis ecthyma staohylococcal scalded skin syndrome superinfections of other skin diseases e.g leg ulcers, atopic eczema
conditions caused by streptococcus pyogenes
impetigo cellulitis ecthyma eysipelas scarlet fever necrotising fasciitis superinfects other skin diseases e.g leg ulcers
PVL toxin - panton valentine leukocidin
s.aureus toxin
pore forming, painful, multi site, recurrent and present in contact
painful
necrotising fasciitis, pneumonia, purpura fulminans
preventing PVL infection
close contact contaminated items crowding cleanliness cuts
treatment of PVL infection
antibiotics
nasal ointment
chlorhexidine
treat any contacts
what is folliculitis
follicular erythema, can be pustular
infections of non infectious (HIV)
treated by antibiotics - erythormicin
incision and drainage for furunculosis (large)
what is pseudomonal folliculitis (hot tub)
pseudomonas aeruginosa
associated w moisture, 1-3 days post exposure to hottub etc
self limiting
furuncle vs carbuncle
furuncle - deep abcess of one follicle
carbuncle - deep abscess of several adjacent follicles (can cause cellulitis or septicaemia)
what is cellulitis
infection of lower dermis/subcut tender swelling will ill defined blanching erythema/odemea usually strep pyogenes of s.aureus odema predisposes treated by systemic antibiotics
what is impetigo
superficial bac infection, honey coloured crust
staphylococcus
face
topical and systemic antibiotics
what is impetiginisation
infection of atopic eczema
what is ecthyma
severe impetigo
punch out ulceration
usually lower extrems
what is erysipelas
raised red plaque, sharp demarcation and painful
infection of deep dermis and subcut
face or limb
history of fever, malaise, headache
treatment IV antibiotics
corynebacterium causes
erythasma - in places that rub e.g armpits
pitted keratinolysis - on sole of foot
scalded skin syndrome
neonates, immunocompromised
erythema - blisters (bullae) - wrinkle and exfoliate
staphylococcus aureus
infection at distant site - not cultured from peeling skin
resembles TEN/SJS
what is toxic shock syndrome
group A s.aureus
fever, hypotension, diffuse erythema, involvement of systems, mucus membranes and haem
what is necrotising fasciitis
initial dusky (blue) induration (hard) followed by rapid necrosis potentially fatal synergistic - strep,staph etc mri aids diagnosis treat with broadspectrum IV antibiotics
what is anthrax
painless necrotic ulcer + oedema + lymphadenopathy
from contact with hide, bone, wool
what is lyme disease
target shaped (annular erythema)
infected tick bite
carditis and arthritis and neuroborriolis
what is tularaemia
infected bite, painful ulcer
ucleroglandular - papule and ulcer on top of each other
herpes simplex virus dermatology
oral, genital, whitlow, eczema herpeticum
swab and PCR
treat w oral acyclovir, IV if high risk or severe
what is oral HSV
primary and recurrent vesicular eruptions
transmission can occur asymptomatically
HSV-1 oral
HSV-2 genital
how does HSV travel within person
replicates at site of infection
travels via dorsal root ganglia
what is herpetic whitlow
HSV 1 on digits
pain swelling and vesicles
misdiagnosed as paronchyma/dactylitis
what is eczema herpeticum
monomorphic punched out erosions/excoriated vesicles
medical emergency
varicella zoster virus
chickenpox
shingles - reactivation
itchy, small, can scab
highly contagious
hand foot and mouth disease
coxsakie
measles
spreads from trunk to extremities
small papules
what are warts
herpes
self limiting
but careful in immunocompromised
what is ORF
parapoxvirus
exposure to sheep/goats
goes away on its own
what is molluscum contagiosum
poxvirus
children n immunocompromised
resolve spontaneously
notable fungal infections
candidiasis - candida albicans - warm moist areas (diabetes M)
aspergillosis - lungs aspergilous
what is scabies
sarcoptes
white burrows by female
then hatch eggs under skin
lice
hair
body
clothes
bedbugs
itchy weals, alone at night, painless
need fumigation
