Exam 1 Flashcards
cryptococcus diagnosis
india ink stain, antigen test
fungal pneumonia in immunocompromised patients
pneumocystis jirovecii or cryptococcus
pneumocystis diagnosis
special stains, PCR
pneumocystis chest xray
diffuse bilateral ground glass opacities
when to initiate pneumocystis prophylaxis
CD4<200
dermatophytes
cluster of superficial skin fungi that cause tinea infections
dermatophytes colonize ____
keratinized stratum corneum
how long to take meds for onychomycosis
3 months
non-dermatophyte cutaneous mold
malassezia furfur
tinea versicolor causative agent
malassezia furfur
tinea versicolor diagnosis
“spaghetti and meatballs” on KOH prep
subcutaneous mold
sporotrichosis
sporotrichosis causative agent
sporothrix schenckii
sporotrichosis mechanism
found in soil, follows traumatic implantation
sporotrichosis presentation
chronic, localized skin infection - nodular ulcerated lesions
what is associated with “fungus ball” in sinuses
rhizopus, mucor
where can zygomycosis manifest
rhino/facial/cranial, lungs, GI tract
complications of zygomycosis
emboli, tissue necrosis
aspergillus aka
black mold
aspergillus sites
body cavities, ear canal, invasive lung disease
dimorphic fungi
blastomyces, histoplasma, coccidioides
where is blastomyces endemic
mississippi and Ohio river valleys, great lakes region
extrapulmonary manifestations of blastomyces
skin, osteomyelitis, CNS, GU tract
where is histoplasma endemic
southeastern US, mid-Atlantic states
extrapulmonary manifestations of histoplasma
bone marrow, blood, CNS, lymph nodes
coccidioides endemic
Southwestern US
extrapulmonary manifestations of coccidioides
erythema nodosum/multiforme, meningitis, bone, arthralgia, fatigue, fever, myalgia, headache, night sweats, weight loss
culture of coccidioides
white fuzzy growth on blood auger - don’t open the plate
pulmonary manifestations of coccidioides
chronic cough, dyspnea, hemoptysis, pleuritic chest pain
coccidioides aka
valley fever
coccidioides diagnosis consideration
TB mimic
fungal infection chest x-ray appearance
multiple small nodules
fungal infection diagnosis considerations
require selective culture media for 21 days, special stains, special testing
special testing for aspergillus
EIA test
special testing for endemic mycoses
immunodiffusion
immunodiffusion
IgM antibodies to endemic mycoses
other special test for fungi
complement fixation
non-systemic fungal treatment
Imidazoles
imidazoles examples
ketoconazole, miconazole, clotrimazole
systemic fungal treatment
triazoles
triazoles examples
fluconazole, itraconazole, voriconazole, posaconazole
which triazoles are PO only
itraconazole, posaconazole
which triazoles are IV/PO
fluconazole, voriconazole
which triazoles are for candida
fluconazole
which triazoles are for aspergillus
itraconazole, voriconazole
which triazoles are for dimorphic fungi
fluconazole
what is posaconazole used for
other invasive molds
cryptococcus treatment
amphotericin IV plus flucytosine PO
yeasts on skin/mouth treatment
nystatin
dermatophyte treatments 2nd line
terbinafine topical, griseofulvan PO
pneumocystis treatment
PO Bactrim
terbinafine tx considerations
monitor LFTs, lengthy course of treatment
antifungals are metabolized by ___
liver
which antifungal has black box warning for cardiomyopathy
itraconazole
how to avoid some amphotericin side effects
premedicate with antihistamines
normal skin flora
staph aureus, staph epidermitis, strep pyogenes, p. acnes, candida albicans
normal nasopharynx flora
strep pneumonia, h. influenzae, moraxella catarrhalis
normal mouth flora
strep viridans, actinomyces, candida albicans
normal pharynx flora
strep pyogenes, kingella kingae (peds)
normal GI flora
enterobacteriacea (e coli, klebsiella, enterobacter), enterococcus, candida
normal vaginal flora
strep agalactiae, actinomyces, gardnerella vaginalis, candida albicans
mutualism
both the host and microbe benefit
commensalism
one partner of relationship benefits (usually microbe) and the other partner (usually the host) is neither harmed nor benefitted
parasitic relationship
the microbe benefits at the expense of the host
pathogenic relationship
the microbe causes damage to the host
opportunistic pathogens definition
only cause disease in those with a compromised immune defense
opportunistic pathogens due to T-cell immune compromise
pneumocystis pneumonia, cytomegalovirus colitis
opportunistic pathogen due to patients receiving broad-spectrum abx
c diff colitis
opportunistic pathogen in patients with intravenous catheters
staph epidermidis bacteremia
frank pathogens definition
always associated with disease
examples of frank pathogens
neisseria, shigella, HIV
facultative pathogens definition
can be either normal flora or pathogenic
majority of organisms that cause disease are ___
facultative
examples of facultative pathogens
staph aureus, e coli
gram positive are usually what morphology
cocci or bacillus
obligate aerobes
mycoplasma tuberculosis, pseudomonas, nocardia, bacillus
obligate anaerobes
bacteriodes fragilis, fusobacterium, clostridia, actinomyces, peptostreptococcus
gram positive bacteria characteristics
thick peptidoglycan layer that holds the crystal violet stain
gram negative bacteria characteristics
thin peptidoglycan layer that decolorizes and then holds the safranin (counterstain)
common causes of neonatal meningitis
e coli, group B strep, listeria
common causes of infant/toddler meningitis
strep pneumo, neisseria, hib, group B strep, e coli
common causes of teen/young adult meningitis
neisseria, strep pneumo
common causes of adults >50 meningitis
strep pneumo, neisseria, Hib, group B strep, listeria
treatment for neonatal meningitis
ceftriaxone, ampicillin
treatment for infant/pediatric meningitis
ceftriaxone, vanc
treatment for older adults meningitis
ceftriaxone, vanc, ampicillin
bacteria not characterized by gram stain
mycobacteria, nocardia, mycoplasma, chlamydia, rickettsia, treponema
why can’t mycobacteria/nocardia be characterized by gram stain
mycolic acids and lipids in cell wall don’t allow stain to penetrate completely
why can’t mycoplasma be characterized by gram stain
no cell wall
why can’t chlamydia/rickettsia be characterized by gram stain
obligate intracellular organisms
why can’t treponema be characterized by gram stain
too small
what mechanisms are used by extracellular bacteria to evade an immune response
formation of biofilms, blockade of opsonization/phagocytosis by binding proteins, production of toxins to escape phagosomes, prevention of phagosome-lysosome fusion, induced uptake by non-phagocytic cells
gram negative rods lactose fermenters
e coli, klebsiella enterobacter
gram negative rods non-lactose fermenter
pseudomonas, e. coli, proteus, salmonella, shigella
gram positive cocci catalase positive
staph aureus, coagulase-negative staph
gram positive cocci catalase negative beta hemolytic
strep pyogenes, strep agalactiae
gram positive cocci catalase negative alpha/non hemolytic
strep pneumo, strep viridans, enterococcus
test for mycobacteria
acid fast
test for nocardia
modified acid fast
test for chlamydia
PCR
test for rickettsia
antibody titer
test for treponema
dark-field microscopy
bronchitis is usually due to ____
respiratory viruses
bronchiolitis pathogen
RSV
bronchiolitis diagnosis
rapid antigen or PCR testing of nasopharyngeal swab
bronchiolitis risk factors
infants, especially premature, age 6 months or younger. And children with congenital heart or chronic lung disease
bronchiolitis recommended therapy
maintain nutrition, hydration, and oxygen saturation over 90%
croup pathogen
parainfluenza virus
croup ssx
barking cough, stridor, labored/noisy breathing
croup prognosis
self-limiting in 3-5 days
croup treatment
keep child calm, using humidified or cool air. Signle dexamethasone shot can be given. Racemic epi only given in severe cases.
organisms causing acute pneumonia
strep pneumo, haemophilus influenzae, moraxella catarrhalis, legionalla
organisms causing atypical pneumonia
mycoplasma pneumoniae, chlamydia pneumoniae, SARS-COVID19, flu A/B, adenovirus, RSV, rhinovirus
legionella morphology
gram negative bacilli
legionnaires infectivity
doesn’t spread person to person, but spreads through mist, usually associated with community outbreaks
risk factors for legionnaires
> 50, weak immune systems, chronic lung disease, heavy tobacco use
legionnaires presentation
may be asymptomatic or cough/fever/chills, SOB, myalgias, headaches, diarrhea
most common pathogen for aseptic meningitis
enterovirus
3 forms of fungi
yeasts, molds, dimorphic
most common yeast species
candida albicans
candida albicans diagnosis
budding yeast with pseudohyphae visible on gram stain
candida albicans skin infection ssx
deep red itchy rash with satellite lesions
“notable yeasts”
candida albicans, cryptococcus, pneumocystis
which yeast causes pneumonia and meningitis in immunocompromised patients
cryptococcus
cryptococcus yeast characteristics
encapsulated budding yeast visible with india ink stain
cutaneous molds
dermatophytes, malassezia furfur
types of dermatophytes
trycophytan, microsporum, epidermophytan
malassezia furfur causes what conditions
tinea versicolor, seborrheic dermatitis
tinea versicolor ssx
hypo or hyperpigmentation of skin
what are the invasive molds
rhizopus, mucor, aspergillus
causative agents of zygomycosis
rhizopus, mucor
which mold causes emboli and necrosis of tissue
zygomycosis
where does zygomycosis invade
rhino-facial-cranial area, lungs, GI tract
black mold
aspergillus
where does aspergillus colonize
body cavities, ear canal, lungs
ingestion of aspergillus
can contaminate foods and form toxins
side effects of triazoles
GI intolerance, hepatotoxicity due to effects on CYP450, rash, QT prolongation
side effects of amphotericin B
rigors, fever, chills, hypoxia, dyspnea, local phlebitis, nephrotoxicity, muscle/joint pain
mycoplasma pneumoniae aka
“walking pneumonia”
mycoplasma pneumoniae diagnosis consideration
bacterium is very small and cannot be gram stained or grown with traditional cultures - can use cold agglutinin
2nd most common cause of CAP
mycoplasma pneumoniae
mycoplasma pneumoniae presentation
mild ssx, persistent cough for weeks to months
who does mycoplasma pneumoniae usually affect
people under 40 and those in crowded settings
mycoplasma pneumoniae transmission
spreads via droplets
mycoplasma pneumoniae chest x ray
may be normal
mycoplasma pneumoniae treatment
normally self-limiting but may use azithromycin or doxy
chlamydia pneumoniae type of bacterium
obligate intracellular
chlamydia pneumoniae transmission
respiratory droplets
chlamydia pneumoniae ssx
similar to m. pneumoniae mild with gradual onset and prolonged cough of 2-6 weeks
chlamydia pneumoniae diagnosis
PCR (usually not performed), CXR may be normal
chlamydia pneumoniae treatment
usually self-limiting but may use azithromycin or doxy
general ssx of atypical pneumonias
`subacute presentation with milder ssx, moderate sputum production, no consolidation
chest x-ray atypical pneumonia
may be normal or may see diffuse interstitial infiltrates
atypical pneumonia wbc
moderate elevation
nosocomial pneumonia pathogens
MRSA, pseudomonas, enterobacteriaceae (e coli, acinetobacter)
aspiration pneumonia pathogens
peptostreptococcus, fusobacterium, klebsiella
pathogen associated with secondary bacterial pneumonia after influenza infection
staph aureus
pathogens associated with lung abscess and necrotizing pneumonia
oral anaerobes, staph aureus, strep pneumo, klebsiella
pathogens associated with chronic pneumonia
nocardia, actinomyces, TB, non-TB mycobacteria, endemic mycoses
causes of neonatal pneumonia
group B strep, e.coli
causes of pneumonia specific to elderly
gram negative bacilli
what does rust-colored sputum suggest
strep pneumo
antivirals for pneumonia due to influenza
oseltamivir, zanamivir
abx for pneumococcal pneumonia
amoxicillin or augmentin, azithromycin, doxycycline, levofloxacin
abx for atypical pneumonia
azithromycin, doxycycline, levofloxacin
abx for pneumoncystis pneumonia
trimethoprim/sulfamethoxazole
new antiviral for influenza
baloxavir marboxil (Xofluza)
when to initiate antivirals for flu
within 48 hours of ssx onset
mycobacteria culture considerations
require 4-6 weeks to grow, requires 3 consecutive morning sputum samples - PCR testing is sometimes available
mycobacteria characterization
acid-fast bacilli
when does primary TB infection occur
after inhalation of bacilli
CXR latent TB
can be normal, can see granulomas/cavitary lesions
are patients contagious with latent TB
no, as long as ssx are not present
what is latent TB
bacteria live in the body without making Pt sick
latent TB sputum culture
will be negative
how to diagnose latent TB
tuberculin test or IFN-gamma release assay
what percept of latent TB will become active
5-10%
active TB ssx
gradual onset of fever, weight loss, fatigue, hemoptysis
active TB transmission
airborne
active TB complication
inflammatory response can result in necrosis and structural collapse of lung
active TB CXR
hilar lymphadenopathy, apical lobes affected
when/how to read TB skin test
measure induration (not erythema) at 48-72 hours
5 mm is positive TB test for what groups
HIV, close contacts of active TB, organ transplants, abnormal CXR
10 mm is positive TB test for what groups
recent arrivals from high-prevalence countries, IV drug users, residents of long-term care facilities, healthcare workers, comorbid conditions (including leukemia/lymphoma), children under 5
15 mm is positive TB test for what groups
everyone
active TB treatment
rifampin, INH, pyrazinamide, ethambutol
rifampin side effects
reddish-orange secretions
INH side effects
peripheral neuropathy, fulminant hepatitis
how to prevent neuropathy with INH
administer with vitamin B6
pyrazinamide side effects
photosensitivity
ethambutol side effects
blurred/changed vision, other eye effects
latent TB treatment
9 months of INH
biofilm treatment principles
remove infected device, surgical debridement, systemic dual abx therapy with one of them being rifampin
some infections creating biofilms
endocarditis, osteomyelitis, chronic wounds/infections, bronchitis from CF, periodontal disease, bacterial prostatitis
why are bacteria in biofilms more resistant to bacteria
decreased metabolic rate of bacteria, increased expression of drug resistant genes, abx may not penetrate biofilm
which organisms account for 80% of infective endocarditis
streptococci (viridans, enterococcus), staphylococci (staph aureus and coagulase negative)
vascular phenomena of infective endocarditis
emboli, hemorrhages (splinter, intracranial, conjunctival), painless Janeway lesions
immunologic phenomena of infective endocarditis
glomerulonephritis, painful osler nodes, roth spots, rheumatoid factor
criteria for infective endocarditis
Duke criteria: 2 major OR 1 major + 3 minor OR 5 minor
predisposing conditions for infective endocarditis
dental procedures, IV drug use, prosthetic heart valves, rheumatic heart disease
right-sided endocarditis predisposing factor
IV drug use
most common organism associated with right-sided endocarditis
staph aureus
most commonly affective valve in right-sided endocarditis
tricuspid
acuity and vascular involvement for right-sided endocarditis
acute, pulmonary vascular involvement
left -sided endocarditis predisposing factors
acquired valvular disease, congenital heart disease
most common organisms associated with left-sided endocarditis
strep viridans, staph aureus
most commonly affective valve in right-sided endocarditis
mitral
acuity and vascular involvement for left-sided endocarditis
acute or subacute, systemic vascular involvement
CV physical exam/echo findings for infective endocarditis
new regurgitant murmur, vegetations on valves
frequent contaminants of blood cultures
staph epidermidis, bacillus, diphtheroids
causes of false positive blood cultures
poor skin antisepsis, poor technique, blood came from central line, only one set collected
causes of false negative blood cultures
abx initiated prior to collection, slow-growing organism or one that is difficult to culture, not enough blood
organisms that are difficult to culture
legionella, bartonella, coxiella, rickettsia, chlamydia
when to collect blood cultures
when fever spikes
how much blood to collect for cultures
at least 10 mL per bottle
what does a set of blood cultures consist of
bottles for aerobic and anaerobic cultures
how to collect blood cultures
2 sets each from different venipuncture sites
categories of risk factors for bacteremia
immune dysfunction, disruption of epithelium, obstruction of drainage conduit or abscess
causes of immune dysfunction as risk for bacteremia
neutropenia, age, immunosuppressive meds, genetics
causes of disruption of epithelium as risk for bacteremia
trauma, surgery, bites, central venous catheters
causes of obstruction of drainage conduit/abscess as risk for bacteremia
choledocolithiasis, nephrolithiasis, diverticulitis, hepatic abscess
examples of bloodstream infections
primary bacteremia, infective endocarditis, central line associated, bacteremia secondary to focal infections
mortality rate for sepsis
14-37%
sepsis criteria for inpatient
SOFA acute change of at least 2 points
major elements of SOFA criteria
respiration, coagulation, bilirubin, BP, GCS, creatinine
sepsis definition
life threatening organ dysfunction caused by a dysregulated host response to infection
septic shock definition
sepsis and vasopressor therapy needed to increase MAP to at least 65 and lactate over 2 despite adequate fluid resuscitation
indicators of sepsis
temp over 38 or under 36, HR over 90, tachypnea, WBC over 12 or under 4, SBP under 90, lactate over 1
what is a hordeolum/stye
impacted eyelash follicle/gland
hordeolum/stye pathogen
staph aureus
hordeolum/stye treatment
warm compresses (abx drops usually aren’t useful)
what is a chalazion
impacted gland on the back of the eyelid
chalazion pathogen
staph aureus
chalazion tx
abx drops
most common conjunctivitis etiology
adenovirus
when to use abx for conjunctivitis
if no URI ssx and in one eye only
bacterial keratitis
corneal abrasion from contacts
bacterial keratitis pathogen
MSSA, strep pneumo, pseudomonas
herpes keratitis appearance on exam
dendritic lesion
herpes keratitis tx
oral or topical acyclovir plus topical steroid drops and emergent specialist referral
preseptal cellulitis cause
scratch or peri-ocular skin infection
preseptal cellulitis ssx
swollen, erythematous eyelid
preseptal cellulitis pathogens
staph aureus or strep pyogenes
preseptal cellulitis tx
keflex
what is orbital cellulitis
infection in the connective tissue posterior to orbital septum
orbital cellulitis cause
contiguous spread from sinus cavity
orbital cellulitis ssx
swollen, eryhtematous eyelid plus proptosis, abnormal EOM, double vision, pain with eye movement
orbital cellulitis pathogens
strep pneumo, haemophilus, moraxella
orbital cellulitis tx
emergent referral for IV abx and drainage of abscess
most common pathogen of otitis media
strep pneumo
why is otitis media more common in peds
flat position of eustachian tubes
otitis media presentation on exam
bulging and eryhtematous tympanic membrane
initial treatment of otitis media
amoxicillin or cephalosporin
what is serous otitis media
often viral with dull, injected, or possibly retracted tympanic membrane
what is mastoiditis
spread of otitis media to mastoid cells of temporal bone
causes of otitis externa
pseudomonas, aspergillus
swimmers ear pathogen and ssx
pseudomonas, green mucoid discharge
otitis externa tx
abx ear drops
most common etiology of pharyngitis in adults
adenovirus
bacterial etiology of pharyngitis
strep pyogenes (group A strep), arcanobacterium
tx of bacterial pharyngitis
penicillin/amoxicillin
tonsillitis/peritonsillar abscess ssx
unilateral tonsil enlargement, displaced uvula, drooling, hot potato voice
tonsillitis/peritonsillar abscess tx
PCN/amoxicillin, abscess drainage, prednisone
epiglottitis ssx
mild stridor, drooling, trouble swallowing - palliation on sitting up or leaning forward
epiglottitis imaging
thumb sign on soft tissue neck x-ray
epiglottitis tx consideration
evaluate in monitored environment due to airway issues
most common pathogen in retropharyngeal abscess
strep pyogenes (group A strep)
retropharyngeal abscess presentation
similar to epiglottitis plus trismus
retropharyngeal abscess tx
medical emergency: IV abx and surgical drainage
what is ludwig’s angina
infection of the bilateral submandibular space
when is ludwigs angina seen
in HIV patients
Ludwigs angina tx
medical emergency - airway management, IV abx and surgical drainage
what is parotitis
inflammation/infection of parotid gland that can be viral or bacterial
most common viral parotitis
mumps (can also be EBV, HIV)
most common bacterial parotitis pathogens
staph aureus, strep viridans, anaerobic oral flora (peptostreptococcus/fusobacterium)
what is sialadenitis
infection/inflammation of any salivary gland that is usually bacterial with same organisms causing parotitis
what does sialadenitis usually occur
due to salivary gland blockage
tx of parotitis and sialadenitis
beta lactamase inhibitor like augmentin or clindamycin. Also need sialogogues to stimulate saliva formation and gentle massage of gland
mumps ssx
asymptomatic, swollen/painful salivary glands, fever, HA, fatigue, anorexia
mumps tx
2 weeks of symptom relief
mumps complications
orchitis, hearing loss, meningitis/enchephalitis
mumps diagnosis
viral culture of buccal mucosa, PCR testing
methods of spread of organisms to CNS
hematogenous, contiguous, direct inoculation, neuronal
most common route for organisms to spread to CNS
hematogenous
what organisms transmit to CNS via neuronal route
herpes, rabies
differences in CNS infections
blood brain barrier, no lymphatics, little complement: Difficult for infections to get in and difficult to treat them
meningitis main ssx
meningismus (headache, nuchal rigidity, photophobia)
acute meningitis is usually
bacterial
subacute meningitis is usually
viral but may be bacterial
chronic meningitis is usually
mycobacterial or fungal
main ssx of encephalitis
altered mental status, +/- focal deficits
most common causative pathogens of encephalitis are ___
viruses
brudzinksi’s sign
involuntary flexion of knees and hips following passive flexion of neck while supine
kernig’s sign
while the thigh is flexed at hip and knee at 90 degree angles, extension of knee is painful
diagnosis of meningitis without signs of ICP is via
Lumbar puncture
contraindications to LP
increased ICP, focal deficits, significant coagulopathy, lumbar soft tissue infection
standard LP tests
cell count with diff, glucose, protein, gram stain, bacterial culture
CSF nucleated cells in bacterial meningitis
> 1000
%PMNs in bacterial meningitis
> 50%
glucose in bacterial meningitis
<40
protein in bacterial meningitis CSF
> 200
CSF nucleated cells in viral meningitis
<1000
%PMNs in viral meningitis
PMNs then lymphocytes
glucose in CSF viral meningitis
WNL
protein in CSF in viral meningitis
50-100
CSF nucleated cells in TB/fungal meningitis
100-500
%PMNs in TB/fungal meningitis
PMNs then lymphocytes
CSF glucose in TB/fungal meningitis
less than 40
protein in fungal meningitis
50-100
protein in TB meningitis
> 200
first-line treatment for pediatric and adult meningitis
ceftriaxone and vancomycin
treatment for neonatal meningitis
ceftriaxone and ampicillin
treatment for geriatric meningitis
ceftriaxone, vancomycin, ampicillin
pathogens in neonatal meningitis
e coli, group B strep, listeria
what pathogens for meningitis are common to all age groups (except neonates)
strep pneumo, neisseria
what pathogen causes meningococcal meningitis
neisseria meningitidis
transmission of meningococcal meningitis
respiratory droplets
complications of meningococcal meningitis
neurological deficits, hearing loss, limb loss, sepsis
treatment for meningococcal meningitis
IM ceftriaxone +/- rifampin or cipro
vaccine for meningococcal meningitis age given
1st dose age 11-12, booster age 16-18
prophylaxis for meningococcal meningitis exposures
2 days of ceftriaxone/rifampin or single dose of cipro
treatment for strep pneumo meningitis
dexamethasone and then vancomycin plus 3rd generation cephalosporin
preventive vaccines for meningitis
Hib, strep pneumo, neisseria
when to do droplet precautions after initiation of abx for meningitis
first 24 hours
most common cause of aseptic meningitis
enteroviruses
most common season for viral meningitis
late summer
causes of viral meningitis
varicella zoster, HSV, enteroviruses (coxsackie, echo), CMV
treatment for varicella zoster and HSV meningitis
acyclovir
treatment for CMV meningitis
gancyclovir
treatment for meningitis due to enteroviruses
supportive care
what is required for control of HSV infection
cell-mediated immunity
encephalitis implies involvement of the ____
brain parenchyma
encephalitis ssx
headache, abnormal behavior, seizures, +/- fever/meningismus
viral causes of encephalitis
HSV, rabies, arboviruses, West Nile
JC virus causes what complication in patients taking monoclonal antibodies
progressive multifocal leukoencephalopathy
ssx of brain abscess
fever, headache, focal deficit, vomiting, seizures, mental status changes
bacterial causes of brain abscess
mixed anaerobes, staph aureus, nocardia
other causes of brain abscesses
toxoplasma, cryptococcoma, tuberculoma
methods of pathogen spread to brain to cause brain abscess
hematogenous, contiguous, post-trauma
methods of pathogen spread to spinal cord to cause spinal epidural abscess
hematogenous or contiguous
what conditions may be associated with spinal epidural abscess
discitis, vertebral osteomyelitis, psoas abscess
spinal epidural abscess diagnosis
MRI, needle biopsy for cultures, PPD, fungal serology, etc
causative pathogens in spinal epidural abscess
staph aureus, gram negative rods, streps, TB, fungi
clinical features of simple cellulitis
poorly demarcated erythema, edema, warmth, tenderness
clinical features of erysipelas
well demarcated erythema, edema, warmth, tenderness, spreads through lymphatics
clinical features of necrotizing fasciitis
pain out of proportion to exam, edema, skin necrosis, bullae, cutaneous numbness, fever, crepitus
clinical features of abscess
erythema, edema, warmth, tenderness, fluctuance
clinical features of impetigo
superficial, intra-epidermal vesicles, “honey-crusted”
simple cellulitis pathogens
staph aureus, group A strep (pyogenes)
erysipelas pathogen
group A strep
necrotizing fasciitis pathogens
strep pyogenes, staph aureus, clostridium perfringens, enteric bacteria, polymicrobial
fournier’s gangrene site pathogens
GU, polymicrobial
abscess pathogens
staph aureus, anaerobes (pilonidal abscess)
impetigo pathogens
group A strep, staph aureus
hot tub folliculitis pathogen
pseudomonas
cellulitis is a ___ diagnosis
clinical
characteristics of mild SSTI
local symptoms only
characteristics of moderate SSTI
<2 signs of systemic infection
characteristics of severe SSTI
failed PO abx and/or have systemic signs of infection, and/or immunocompromised, and/or ssx of deeper infection
initial treatment for all purulent SSTIs
I&D
when to C&S purulent SSTIs
moderate/severe
empiric abx for moderate purulent SSTI
TMP/SMX or doxycycline
treatment for moderate purulent SSTI MRSA
TMP/SMX
treatment for purulent moderate SSTI MSSA
dicloxacillin or cephalexin
empiric tx for severe purulent SSTI
Vancomycin or ceftaroline etc
treatment for severe purulent SSTI MRSA
vancomycin or ceftaroline etc
treatment for severe purulent SSTI MSSA
nafcillin or cefazolin or clindamycin
tx for mild nonpurulent SSTI
oral abx: PCN, cephalosporin, clindamycin
tx for moderate nonpurulent SSTI
IV PCN, ceftriaxone, clindamycin
tx for severe nonpurulent SSTI
emergency surgical consult plus empiric tx of vanc plus pip/taz
nonpurulent SSTIs include
necrotizing, cellulitis, erysipelas
purulent SSTIs include
furuncle/carbuncle/abscess
SSTI staph/strep abx
cephalexin/ceftriaxone
SSTI with MSSA
dicloxacillin
simple cellulitis abx
doxycycline
tx for impetigo
bactroban/mupirocin ointment
SSTI with MRSA
bactrim
SSTI abx if reactions to other meds
clindamycin
severe SSTI abx
pip/taz and vanc (covers pseudomonas)
PCN+clinda : covers GAS and clostridium for nec fasc
most animal bites are from a ___
dog
pathogen in human bites
eikenella
pathogen in cat bites
pasteurella
pathogen in dog bites
capnocytophaga
bite wound treatment
copious irrigation with exploration for foreign bodies and bone/tendon involvement, leave open when possible or loosely suture
wounds that become infected within 24 hours of bite are often _____
pasteurella
first-line bite prophylaxis
augmentin
when to initiate tetanus prophylaxis after a bite
if it is has been more than 5 years since last immunized
characteristics of nec fasc
rapid spread, brawny edema of site, wooden feeling to tissue, crepitus with worsening perfusion and later anesthesia, sepsis
initial empiric treatment for nec fasc
vancomycin and pip/taz
defined treatment for nec fasc if due to GAS
penicillin and clinda
toxic shock syndrome pathogens
staph aureus, GAS
characteristics of toxic shock syndrome
fever, hypotension, ARDS, coagulopathy, sunburn-like rash, renal/liver failure, necrosis
toxic shock syndrome initial treatment
IV PCN and clindamycin, surgical debridement, IV immunoglobulin
common organisms in hematogenous osteomyelitis
staph aureus, GAS, mycobacterium, staph epidermidis, Hib
vertebral organisms in hematogenous osteomyelitis
staph aureus, staph epidermidis, mycobacterium, GNR, candida
diagnosis of osteomyelitis
bone biopsy/aspiration, blood cultures, PPD/AFB culture
treatment of osteomyelitis
cover for MSSA/GAS and add coverage for MRSA if septic or previous history. Treat with IV abx for minimum 6 weeks
organisms in local infection non-hematogenous osteomyelitis
staph aureus, GNR, anaerobes
Organisms in puncture wounds becoming non-hematogenous osteomyelitis
staph aureus, GAS, polymicrobial, pseudomonas
what pathogen associated with foot puncture wound in diabetic neuropathy
polymicrobial
what pathogen associated with puncture through a tennis shoe
pseudomonas
septic arthritis usually affects how many joints
one
pathogens in septic arthritis
staph aureus, GAS, gonorrhea, salmonella
diagnosis of septic arthritis
bacterial culture of joint aspirate, fluid cell cout/diff, glucose, total protein, blood cultures, STI testing
post-infectious reactive arthritis presentation
polyarticular in larger joints of lower extremities 4-6 weeks after infection
respiratory organisms leading to reactive arthritis
GAS, neisseria meningitides, viruses
GU organisms leading to reactive arthritis
gonorrhea, chlamydia
GI organisms leading to reactive arthritis
salmonella, shigella, campylobacter, yersinia
treatment of reactive arthritis
prednisone
