Inflammation and Infection Flashcards
Most common bacterial infection in children?
impetigo
how is impetigo usually contracted?
person to person
less commonly through fomites
predisposing factors to impetigo?
high humidity
cutaneous carriage
poor hygiene
causative agent
non bullous impetigo of childhood?
Streptococcus pyogenes
causative agent
non-bullous and bullous impetigo (most common cause of both types of impetigo)
Staphylococcus aureus
70-80% of all impetigo is which kind?
non-bullous impetigo
non-bullous impetigo
most commonly affects?
face followed by extremities
non-bullous impetigo - typical beginnings?
typically begins as single lesion - autoinoculation frequently produces multiple adjacent lesions
non-bullous impetigo - early primary lesion – appearance?
erythematous macule with superficial blister (rarely appreciated)
non bullous impetgio - developed lesion?
honey colored yellow crust
do we see lymphadenopathy in non-bullous impetigo?
mild / variably present
complication to have on your radar with non-bullous impetigo from streptococcal ?
up to 5% are associated with post-streptococcal glomerulonephritis
bullous impetigo (percent)
20-30
bullous impetigo body area
any area
Bullous impetigo beginning?
typically begins as single lesion - autoinocculation frequently produces multiple adjacent lesion
bullous impetigo - primary lesion
superficial, flaccid blister that may occasionally demonstrate layered pus
bullous impetigo - older lesion
demonstrate collapsed blister that are often described as having a varnished like appearance
Stapphylococcal scalded skin syndrome/
primarily seen in children less than six - produced by pahge group II strains that produce exoliative toxins - that produce diffuse superficial blisters over large areas of the body
listed under bullous impetigo
Diagnosis of impetigo?
clinical
culture
biopsy (Rarely done)
Impetigo with short chains of gram positive cocci amongst numerous neutrophils?
S pygogenes =
non-bullous impetigo of children
treatment of impetigo?
soak and remove crust
topical antibiotics (limited cases)
systemic antibiotics
topical antibiotic used to treat impetigo?
mupirocin 2% ointment
do systemic antibiotics used to treat impetigo alter post-streptococcal glomerulonephritis risk?
no
common systemic antibiotics
cephalexin
dicloxacillin
azithromycin
clarithromycin
impetigo fucks with what layer of skin
epidermis
cellulitis fucks with which layer of skin
dermis
epidemiology of cellulitis
more common in very young, elderly, immunocompromised, IV drug users, chronic ulcers
post-surgical
increased summer
where do celluitis infections occur through?
breaks in skin - breaks can be microscopic and not clinically noticeable
bacteriology of cellulitis
most commonly associated with (3)
b-hemolytic streptococci (streptococcus pyogenes), staphylococcus aureus, Haemophilus influenza (kids)
What is erysipelas
clinical variant of celluitis in children -
eryspielas - most common bacteriology
b-hemolytic streptococci (streptococcus pyogenes)
What is erysipelas?
St. Elmo’s fire
Cellulitis
Erysipelas common presentation?
most commonly confined to face, less commonly extremities
erysipelas incubation period
2-5 days
erysipelas systemic symptoms
variable
chills, fevers, malaise
erysipelas - primary lesion
sharply demarcated area of erythema (cliff drop border) that demonstrates non-pitting edema (lesions are often painful)
erysipelas - lymphadenopathy?
regional
strictly present
erysipelas infrequent epidermal presentation?
rarely the overlying epidermis may demonstrate bullae, pustules, or hemorrhagic necrosis
cellulitis
most common location
extremities
cellulitis
incubation period
2-5 days
cellulitis
primary lesion
ill defined non-palpable or subtly palpable area of painful erythema that is warm to the touch
cellulitis
older lesion
may demonstrate variable hemorrhage
cellulitis
lymph involvement?
lymphatic streaking commonly present
regional lymphadenopathy frequently present
cellulitis
patients may progress to?
septicemia
cellulitis
diagnosis?
clinical CBC may demonstrate luekocytosis biopsy - may be conistent though organisms are rarely IDd Culture more specific (use leading edge) blood culture - positive in up to 10%
treatment of cellulitis?
correct against?
mild
severe
streptococcal or staphylococcal organisms
mild cases
- oral cephalexin
- oral dicloxacillin
- oral clarithromycin
- oral azithromycin
- oral fluoquinolone antibiotic
severe cases (require hospitalization) - intravenous antibiotics with broad spectrum coverage (e.g. piperacillin/tazobactam or metronidazole plus ciprofloxacin)
true or false
severe cases of cellulitis require hospitalization
true
dermatophyte infection
-
superficial fungal infection - because dermatophytes eat keratin
dermatophyte infection acquired?
human
animal
fomite
soil
dermatophyte food source
keratin (top layer of skin / hair / nails)
socks and jocks dermatophyte?
epidermophyton - tinea cruris
most common dermatophyte?
trichophyton - tinea capitis / corporus
fluorescent dermatophyte in tinea capitis?
microsporum
most common cutaneous dermatophyte
trichophyton rubrun
most common tinea pedis
trichophyton metagrophytes
most common tinea capitis
trichophyton tonsurans
most common fluorescent tinea capitis
microsporum canis