Skin and Soft Tissue Infections Part 1 Flashcards
Skin and soft tissue infections are one of the most common infections where??
in BOTH the community and in hospital settings
which layers of the skin may be involved in skin and soft tissue infections
may involve any or all layers
including epidermis, dermis, hypodermis, fascia, and muscle
true or false
skin and soft tissue infections are not a big clinical concern because they stay localized
FALSE
they can spread and lead to more severe complications like endocarditis and gram negative sepsis
the MAJORITY of skin and soft tissue infections are caused by what organisms (in general)
gram positive organisms that are on the skin
differentiate between the normal flora ABOVE THE WAIST and the normal flora BELOW THE WAIST
above the waist - primarily gram positive - ie: coagulase negative staph, corynebacterum, MRSA, mssa, strep pyogenes
below the waist - all gram positive present above AND gram negative (enterobacterales, enterococcus)
name 2 NOSOCOMIAL pathogens
pseudomonas aeruginosa
MRSA
true or false
MRSA cannot be community-asssociated
FALSE
it can - there is community-associated MRSA (CA-MRSA)
in general, what are risk factors for skin and soft tissue infections
anything that affects the skin integrity
for example – trauma, inflammation, obesity, breaks in skin, venous insufficiency, etc
what are 2 broad categorizations of SSTIS
purulent (cause pus formation)
and nonpurulent (no pus formation)
name 4 purulent skin and soft tissue infections
folliculitis
furuncle
carbuncle
ascess
name 4 non-purulent SSTIS
impetigo
erysipelas
cellulitis
necrotizing fasciiitis
typically, purulent skin and soft tissue infections are caused by which bacteria?
staph aureus
SO, must cover for MRSA in empiric coverage
another name for a boil
is it purulent or non-purulent SSTI
furuncle
purulent
define folliculitis
where is the pus?
very superficial purulent infection of the hair follicles
the pus is only in the EPIDERMIS
differentiate between a furuncle and a carbuncle
a furuncle has a single sinus tract. is an inflammatory, draining nodule that involves a hair follicle (purulent)
a carbuncle is when adjacent furuncles (boils) come together to form a single painful area – forms DEEP masses tha open into MULTIPLE sinus tracts
what is an abscess
collection of PUS (purulent) within the dermis and the deeper skin tissue
treatment for folliculitis
resolves on its own
use warm, moist compress
if however it does NOT resolve on its own, use mupirocin twice a day for 5 days, or even bacitracin
furuncle, carbuncle, and abscess treatment (mild vs moderate vs severe)
mild - incision and drainage. ALWAYS done regardless of severity + adjunctive antibiotic if the abscess is greater than 5 cm
moderate - incision and drainage + culture and sensitivity + empiric PO AB’s against MRSA
severe - incision and drainage + culture and sensitivity + empiric IVVVV antibiotics against MRSA
as a reminder, name 12 AB’s that cover MRSA
bactrim
doxycycline
tigecycline
vancomycin
daptomycin
linezolid
clindamycin
televancin
oritavancin
dalbavancin
delafloxacin
ceftaroline (5th gen ceph)
differentiate between when a purulent infection (aside from folliculitis - so a furuncle, carbuncle, or an absess) can be considered mild vs moderate vs severe when determining treatment
mild - no systemic symptoms
moderate - 1 systemic symptom (ie- fever, white count, hypotension, rapid breathing)
severe - 2 or more systemic or severe signs of the infection. OR failed incision and drainage AND PO antibiotics
true or false
in a mild purulent SSTI, there is no antibiotic therapy used
TRUE bc not recommended by IDSA guideleine
HOWEVER, new literature suggests there may be a benefit of using antibiotics against MRSA
-shows lower risk of treatment failure, lower risk of ascess recurrence, and lower risk of hospitalization and surgical procuedure
THEREFORE – if the infection size of the mild SSTI is GREATER THAN 5 CM, we recommend oral antibiotics like doxy or bactrim
EMPIRIC antibiotic treatment for MODERATE SSTI
PO bactrim or doxycycline
(want to cover MRSA!!)
empiric treatment for SEVERE SSTI
IV antibiotics that cover MRSA -
vanco, dapto, linezolid, telavancin, or ceftaroline
DEFINED treatment for moderate SSTI for:
MRSA vs MSSA
MRSA - bactrim
MSSA - dicloxacillin or cephalexin
DEFINED treatment for SEVERE SSTI for:
MRSA vs MSSA
MRSA - same as empiric (vanco, dapto, linezolid, televancin, ceftaroline)
MSSA - nafcillin or cefazolin (1st gen) or clindamycin (if resistance less than 10-15%)
what to monitor when doing incision and drainage/adjunctive antibiotic for a mild SSTI
watch for signs that the infection is improving
as mentioned, either bactrim or doxy is recommended as empiric treatment for moderate SSTI
what are the dosings and monitoring parameters of each
bactrim - 1 ds tab q12
doxy - 100mg q12
monitoring:
bactrim - SJS (rash), hyperkalemia, renal function (crystalluria - drink water!!), photosensitivity, hematologic toxicity (monitor CBC if on long time)
doxy - photosensitivty, NVD, avoid less than 8 and in pregnant pts
important counseling point for patients on bactrim
photosensitive - stay out sun
STAY HYDRATED to prevent crystalluria bc affects renal function
Vanco dosing for severe SSTI
15mg/kg q12hours
what to monitor when administering vanco for a severe SSTI
therapeutic drug monitoring
infusion reactions (given IV)
renal function
what to monitor when administering daptomycin for a severe SSTI
CPK (can cause increased creatinine phosphokinase)
myopathy/rhabdomyolysis
what to monitor when giving linezolid for a severe SSTI
myelosuppression
thrombocytopenia
optic neuropathy
peripheral neuropathy
serotonin syndrome
which of the drugs given only for SEVERE SSTI as empiric therapy can cause thrombocytopenia?
LINEZOLID
happens around day 7-10 of therapy - very common in older peopl
which of the empiric antibiotics given for SEVERE SSTI is not usually combined with serotenergic meds bc of risk of serotonin syndrome
linezolid
in purulent SSTIS, ______should be streamlined based on ______
empiric therapy should be streamlined based on CULTURE AND SENSITIVTY RESULTS
daptomycin dosing for severe SSTI
4-6mg/kg q24
linezolid dosing for severe SSTI
600mgIV (or PO) q12 hours
ceftaroline dosing for severe SSTI
400mg IV Q12H
typically, the treatment for purulent skin and soft tissue infections lasts….
7-14 days, but it depends on the clinical improvement
true or false
for purulent skin and soft tissue infections, the antibiotics need to be completed for the full 7-14 days, even if clinical improvement has been noted
FALSE
once you see clinical improvement, you can stop them. the lesions do not need to FULLY RESOLVE to stop the antibiotics
what should patients with skin and soft tissue infections (purulent) be educated on?
appropriate wound care to avoid recurrent infections
25 year old female presents with 7cm abscess of right axilla.
no systemic signs of infection and NKA
what is the most appropriate treatment for her
LATER her I&D was sent for culture and came back as METHICILLIN RESISTANT
what is appropriate therapy now? counseling points?
incision and drainage plus bactrim
could also be doxy, but bactrim is best
CONTINUE BACTRIM!!! COVERS MRSA
apply spf, stay hydrated (renal), report any signs of rash, watch for muscle cramping bc sign of hyperkalemia
pt in previous example (on bactrim for MRSA mild SSTI) now complains of a rash since starting bactrim
now what is the best therapy?
doxycycline - its the other first line for mild SSTI and also covers MRSA
define impetigo
contagious SUPERFICIAL infection of the skin, most commonly seen in children
2 broad categorizations of impetigo
bullous vs nonbullous
difference in the cause (bacteria) of bullous vs nonbullous impetigo
bullous - caused by toxin-producing staph aureus
nonbullous - caused by beta hemolytic streptococci and/or staph aureus
which is the most common form of impetigo - bullous or nonbullous?
nonbullous
differentiate between the physical features of bullous impetigo vs nonbullous
nonbullous - small, fluid-filled vesicles that are like pustules that can rupture. has golden yellow crust
bullous - bullae have clear yellow fluid that reptures and is characterized by a thin, light brown crust – associated with ENLARGED LYMPH NODES
treatment for MILD impetigo (just 1 or 2 spots)
topical mupirocin (or even bacitracin) BID for 5 days
treatment for impetigo in which there are multiple lesions OR involving the face
PO antibiotics for 7 days
as mentioned, when there are multiple impetigo lesions or involving the face, use PO antibiotics for 7 days
in general, the agents chose should be active against what??
be specific
STAPH AUREUS
for MRSA - give clindamycin, doxy, or bactrim
for MSSA - give dicloxacillin or cephalexin or augmentin
dependent on RISK FACTORS whether you will give 1 that covers MRSA or not
symptomatic relief (not drugs) that the pt can do for impetigo
help the symptoms by removing the crusts by soaking with soap and warm water
define erysipelas
it is most commonly associated with what bacteria?
cellulitis involving the more superficial layers of the skin and the lymphatics
GROUP A STREP (streptococcus pyogenes)
drug of choice for erysipelas
penicillin (IV or PO - based on the severity)
clinical presentation of erysipelas
continuously red and edematous and indurated (fibrous and hard)
spread peripherally, associated with HIGH FEVER, CHILLS, AND GENERAL MALAISE
which presents with more systemic symptoms - impetigo or erysipelas?
erysipelas
have high fever, chills, and malaise
for impetigo its just the skin that’s really tight and itchy
which PCN are administered IM/IV/PO
and how long for erysipelas
NOTE: skipped penicillin dosing - waiting for her to reply to email
IM - procaine penicillin G
IV - penicillin G
PO - Penicillin VK
7-10 days
true or false
erysipelas does not respond quickly to penicillin treatment
FALSE - it does
marked improvement usually seen within 48 hours of treatment
explain the areas that cellulitis affects
initially it’s just the epidermis and dermis, but may spread to the superficial fascia, lymphatic tissue, and ultimately to the BLOODSTREAM
which 2 bacteria frequently cause cellulitis
group A strep (strep pyogenes)
staph aureus
BOTH ARE GRAM POSITIVE
cellulitis may lead to ______ formation, particularly in what 2 scenarios
abscess
polymicrobial infection or an anaerobic infection
in cellulitis, patients usually have a history of what
wound or trauma
clinical presentation of cellulitis
erythema and edema of the skin, warm to touch and PAINFUL
lesions NOT ELEVATED with poor defined margins
may drain, exudate, or abscess
true or false
in cellulitis, the lesions are elevated and have poorly defined margins
FALSE
not elevated and have poorly defined margins
NONPHARMACOLOGIC management of cellulitis
elevate the area and dont move - to decrease swelling
use cold compresses for pain
use moist heat to help keep the cellulitis local
may need surgical debridement to remove the dead or infected tissue — in COMPLICATED cases
in cellulitis, what can be used to try to keep the infection local?
what about for pain?
what about for swelling?
keep local - moist heat
pain - cold compress
swelling - elevate it and immobilize
what is the term for surgical intervention in cellulitis
debridement
antibiotics can be used in cellulitis - either empiric or directed therapy
when choosing what to give, what should we be looking at ??
the patient’s risk factors and severity
for ex - are they an IV drug user? immunocompromised? is an absess forming? etc
what do we want to cover if cellulitis is purulent vs non-purulent
in mild-moderate cases !!! (outpatient)
non-purulent - just need to cover group A strop
if purulent - cover staph (MRSA)
which 4 drugs can potentially be used to cover MRSA in mild-moderate outpatient purulent cellulitis
(empiric)
bactrim and doxy PO are first line
can consider linezolid or tedizolid but they’re more $$$ and less tolerated
which antibiotics are first line in nonpurulent mild-moderate OUTPATIENT cellulitis
(empiric)
want to cover group A strep (strep pyogenes - gram (+))
use PO beta lactams like pen VK, cephalexin, dicloxacillin
CAN use later gen PO cephalosporins but they’re more money
for mild-moderate outpatient cellulitis (whether purulent or non-purulent) how long does empiric treatment last?
around 5 days but it all depends on the clinical response
