ID Flashcards
1
Q
MC etiologies of meningitis?
A
- bacterial:
strep pneumo
N. meningitidis
H. flu - viral: enteroviruses, HSV, HIV, West Nile, VZV, mumps
- fungal: cryptococcus
- noninfectious: tumor, trauma, brain abscess, subdural empyema, pharm rxn
2
Q
Community acquired vs health care assoc etiologies of meningitis?
A
- community: Strep pneumo N. meninigitis H flu Listeria monocyotgenes (immune compromised)
- healthcare:
staph and aerobic gram neg bacilli
3
Q
Sxs of meningitis?
A
- abrupt onset
- classic triad: fever, nuchal rigidity, change in mental status
- intense HA
- photophobia, lethargy, nausea, vomiting, jt pain, seizures
- mediation duration of sxs b/f presentation: 25hrs (bacterial)
- petechial rash = N. Meningitidis
4
Q
Dx issues w/ CNS infections in elderly?
A
- hard to initially separate meningitis from encephalitis:
both present w/ mental status changes, elderly w/ meningitis less likely to have fever - any infection in elderly can cause delirium in elderly
- if personality change think encephalitis
5
Q
What are red flags in elderly pop when thinking about meningitis?
A
- behavioral changes/personality changes
- seizures
- lack of there source of infection
- HA, nuchal rigidity, exposure to infected persons
- low threshold to do LP
6
Q
Indications for head CT prior to LP?
A
- immunocompromised
- hx of seizure w/in 1 wk prior to presentation
- any of following neuro abnorm:
abnorm LOC
hx of CNS disease (lesion, stroke, focal infection)
PAPILLEDEMA
focal neuro deficit - mandatory in pts w/ possible focal infection
** any evidence of papilledema or focal neuro findings - don;t perform LP b/f getting STAT CT to r/o sig ICP - perform LP immediately in absence of papilledema or focal neuro findings
7
Q
W/U for meningitis? Tx?
A
- blood cultures, CBC, chem 7
- send CSF to lab for cell count, gram stain, culture, glucose, and total protein:
Any + gram stain is dx, WBC in CSF over 1000 if PMNs make up 85% is dx, CSF glucose less than 50% of serum glucose is suggestive - as soon as LP is completed (b/f labs are even back) give 2 gm rocephin IV
- all admitted and rocephin cont at 2 G IV q 12 hrs
- many even w/ proper, rapid tx will die or have permanent CNS deficits
8
Q
Normal CSF values?
A
- pressure: 70-180 mm H2O
- appearance: clear, colorless
- CSF total protein: 15-45 mg/100 ml
- CSF glucose: 50-80 mg/100 ml (or greater than 2/3 of blood sugar level)
- CSF cell count: 0-5 WBCs (all mononuclear) and no RBCs
- chloride: 110-125 mEq/L
9
Q
Bacterial meningitis clues in peds?
A
- occurs MC b/t 2 mo- 2 yrs
- uncomon to develop meningitis form OM and spread is not from direct extension but from systemic spread
- irritability and poor feeding may be only clues in infants
- paradoxical irritability: crying worsens when being held - suggestive of meningitis
10
Q
MC etiologic agents of meningitis in peds pts? How can we prevent this?
A
- strep pneumo
- N. meningitidis
- H flu
- in neonates: consider gram - causes, group B strep
- primary prevention of meningitis:
S. pneumo vaccine
H. flu vaccine
Meningococcal vaccine now available for teens and adults
11
Q
What is menigoencephalitis?
A
- overlap of meningitis + encephalitis
12
Q
What is encephalitis? MC etiology?
A
- inflammation of the brain
- MC caused by viral infections:
HSV-1, HSV-2 are rapidly progressing and life threatening - West Nile, CMV, mumps, EBV
13
Q
What is the diff b/t encephalitis and meningitis?
A
- encephalitis has alt brian fxn and neuro findings: personality changes, paralysis, hallucinations, alt smell, problems w/ speech
14
Q
Sxs of encephalitis?
A
- mild: flu like sxs
- severe:
severe HA, fever, alt consciousness, confusion, agitation, personality changes, seizures, loss of sensation, paralysis, muscle weakness, hallucinations, double vision, perception of foul smells, problems w/ speech or hearing, LOC - children: bulging of fontanels, N/V, body stiffness, inconsolable crying, crying that worsens when picked up, poor feeding
15
Q
W/U and tx of encephalitis?
A
- CT and/or MRI of head
- CBC, CMP
- LP: usual cultures, PCR for HSV1, serology: IgM ab for west nile virus, mumps, EBV
note if RBCs in CSF and nontraumatic tap it is HSV until proven otherwise - tx: Acyclovir 10 mg/kg IV q 8 hrs (empiric tx for HSV b/c it is most deadly)
16
Q
Septic arthritis progression? What jts are most commonly affected?
A
- It is an emergency!!
- when left untx - can destroy a jt in 12-24 hrs
- usually affects only one or few asymmetrical jts
- more commoly affects large jts, esp knee
17
Q
S/S of septic arthritis?
A
- acute or subacute onset of pain
- erythema, swelling and limiting jt motion
- systemic sx (fever, malaise) may be present or absent
- Must do arthrocentesis on any: red, hot, swollen jt
18
Q
What will jt fluid analysis show in septic jt tap?
A
- over 40,000 WBCs in most cases
- send jt fluid for crystals, glucose, cell count, culture
- have to specific culture + sensitivity + r/o gonorrhea
- gram stain of jt fluid will show causative organism in most cases except gonoccal arthritis (80% false negative)
- if GC arthritis is suspected in sexually active pt: do cervical, urethral, or rectal GC cultures as approp for over 90% sensitivity
19
Q
Tx for septic arthritis?
A
- High dose IV abx
- no indication for intra-articular abx
- Rocephin good choice
20
Q
Sxs of bacteremia? Source of infection?
A
- fever, +/- chills, rigors may suggest bacteremia, disorientation, hypotension, resp failure, sepsis, septic shock, skin lesions
- source of infection: resp tract, central venous cath, urinary tract, GI tract, biliary tract, skin, soft tissues
21
Q
Tx for gram - bacteremia?
A
- 25-50% of all blood stream infections (worse off than gram +)
- tx for severe sepsis +/- shock:
gentamicin or tobramycin or amikacin + antipseudomonal cephalosporin like cefepime +/- vanco until cultures come back
22
Q
Tx for gram + bacteremia?
A
- staph aureus leading cause
- empiric tx: vanco
- MSSA: PCN, nafcillin, oxacillin, vanco
- MRSA: vanco or daptomycin
- w/u should include TEE to r/o infectious endocarditis (IV drug use hx)
23
Q
What is sepsis?
A
- clinical syndrome from dysreg inflammatory response to an infection
- infection + some of the following:
temp greater than 38.3, or less than 36C
HR over 90
RR over 20
AMS
sig edema
hyperglycemia w/o hx of DM (glucose over 140)
or - infection + some of the following:
inflammatory: WBC over 12K, or below 4K, WBC w/ over 10% of bands, elevated CRP, elevated procalcitonin - hemodynamic:
hypotension often w/ wide pulse pressure - poor urine output, elevated creatinine, elevated INR, and PTT, low platelets
24
Q
Another definition of sepsis?
A
- infection + some of the following: ileus elevated bili elevated lactate decreased cap refill arterial hypoxemia
25
Q
Tx of sepsis?
A
- supportive and tx most likely source of infection such as bacteremia
26
Q
What is cellulitis? When is it considered an emergency? Tx?
A
- superficial soft tissue infections are rarely emergencies w/ 3 exceptions:
infection around face and hand, cellulitis in presence of diabetes or PVD, local infection w/ presence of leukemia or HIV - cellulitis: acute spreading infection of skin to and through dermis
- all cellulitis, folliculitis, furnuculosis is due to MRSA until proven otherwise, DOC is bactrim and alt = clinda
27
Q
What is impetigo? Tx?
A
- superficial skin infection usually seen in kids due primarily to strep, uncommonly staph
- small vesicles which quickly ruptures and form honey colored crusts
- tx: bactroban
28
Q
What is endocarditis?
A
- infection of endothelial surface of heart, most often the valves
- tough to dx
- may present as acute or subacute
- pts at high risk are those w/ previous valve damage, replacement, or hx of IVDU
- subacute may present w/ anorexia, night sweats and wt loss
- acutely: cardiac failure, stroke due to septic emboli, or cold extremity due to septic emboli
- IVDU: may have tricuspid valve endocarditis and may present w/ bilateral embolic pneumonia
29
Q
What are characteristic but not specific cutaneous lesions of endocarditis?
A
- conjunctival and palatal petechiae
- subungual (splinter) hemorrhages
- osler nodes = tender, erythematous nodules w/ opaque centers which appear on pulp of fingers/toes
- janeway lesions: nontender red or maroon macules or nodules on palms and soles
- dilated eye exam: roth spots (pale oval areas surrounded by hemorrhage) near optic disc
30
Q
Dx tests for endocarditis?
A
- echo: may show valvular vegitation TEE better than TTE
- normocytic, normochromic anemia may be present
- elevated ESR almost always present
- obtain blood cultures and start empiric abx
31
Q
What is TSS?
A
- results from absorption of toxin from localized staph aureus colonization or infection:
hx - tampon use, increasing number of cases now seen from wound or sinus infections
32
Q
S/S of TSS?
A
- short prodrome: fever, myalgias, V/D, pharyngitis
- rapidly develop fulminate shock (SBP less than 80 mmHg) and fever over 102.2 w/ mult organ failure
- a diffuse blanching, macular erythema appears w/ signs of pan-mucosal inflammation, rash fades in 2-3 days, desquamation of hands and feet occurs in all 5-12 days after rash disappears
33
Q
Labs for TSS?
A
nonspecific but represent mult organ system involvement:
- leukocytosis, thrombocytopenia (bone marrow toxicity)
- elevated BUN and Cr (renal toxicity)
- elevated LFTs and bili (liver toxicity)
- sterile pyuria
- elevated CPK (muscle damage)
- decrease serum albumin and total protein due to leaking caps
- blood cultures: will be negative and this is toxin induced
- cultures of source: vagina, wound or sinus: will grow S. aureus
- max supportive care and tx to prevent additional toxin production
34
Q
Presentation of RMSF?
A
- incubation 1 wk
- sudden onset of fever, chills, malaise, myalgias, severe frontal HA
- on the 2nd-5th day: rash appear - pink, macular 1-4 mm in diameter appears on palms, soles, hands feet, wrists and ankles
- over next 24-48 hrs becomes petechial, purpuric, and even gangrenous
- **spreads centripetally
- diffuse edema due to cap leakage, hypotension, splenomegaly, and delirium
- labs may all be normal
- tx: early TCN or doxy (kids: chloramphenicol)
35
Q
Stages of Lyme disease?
A
- stage 1: rash = erythema migrans, gradually expanding area of redness w/ central clearing from bite site, may be accomp by fever, chills, malaise, regional adenopathy
- stage 2: days to weeks after infection, multisystem involvement (heart, liver, neuropathy, muscular), fatigue, lethargy may persist for months
- stage 3: lingers for months to yrs w/ arthritis, neuropathy, acrodermatitis chronica atrophicans
- only lab proof is rising titer seen in paired sera
- best approach is empirical tx: Doxy!!
36
Q
Sxs of malaria?
A
- parasitic infection secondary to plasmodium falciparum (90% of cases)
- sxs occur 12-35 days after exposure and can wax and wane due to parasite load
- uncomplicated cases, sxs: fever, malaise, myalgias, arthralgias, HA
- fevers may be predictable and occur at regular intervals (cyclical fever)
- complicated cases: fever, anemia, splenomegaly, alt consciousness, seizures, ARDS, circulatory collapse, metabolic acidosis, renal failure, liver failure, coagulopathy, DIC, severe anemia, intravascular hemolysis, hypoglycemia
- sxs: can progress rapidly and can be fatal
- PE: pallor, petechiae, jaundice, hepatomegaly, splenomegaly, splenic rupture
37
Q
Dx malaria?
A
- anemia, elevated WBC, low platelets
- dx is clinical and based on parasite dx w/ either giemsa stained visualization of parasites in periph blood smear, antigen or ab tests, molecular techniques for extracting parasite genetic material
38
Q
Tx of malaria?
A
- depends on location where infection was acquired
- chloroquine, quinine, doxy
39
Q
Describe botulism?
A
- it is in soils and marine sediment worldwide
- gram +, rod shaped, spore forming obligate anaerobic bacteria
- 5 forms:
foodborne, infant, wound, adult enteric and inhalation
40
Q
Key features of botulism?
A
- classically described as acute onset of bilateral cranial neuropathies assoc w/ symmetric descending weakness
- other key features:
absence of fever, pt remains responsive, normal or slow HR and norm BP, no sensory deficits w/ exception of blurred vision
41
Q
Testing for botulism?
A
- infants: neg in serum, eval stool for spores and toxin
- foodborne: serum analysis for toxin
- wound: cultures of wound should be +, likely negative serum assays
- adult enteric: eval stool for spores and toxin
42
Q
Tx of botulism?
A
- any s/s or hx suspicious for botulism should be hosp immediately and monitored for signs of resp failure
- 2 botulism-a antitoxin therapies:
equine serum heptavalen bolulism antitoxin (older than 1 yo)
or
botulism immune globin for infants (younger than 1) - abx are only helpful for wound botulism: PCN G and metronidazole
43
Q
Epidemiology of smallpox?
A
- only disease known to be eradicated
- droplet, contact, airborne transmission from person to person
- doesn’t occur until onset of rash
- max infectiousness: days 7-10 of rash
- increased infectiousness if pt coughing or has hemorrhagic form
- anyone under 26 has no immunity
- vaccine b/f or w/in 2-3 days of exposure over 99% effective
- spreads more readily during cool, dry winter
- variola (family poxviridae) - part of orthopoxviruses (including chickenpox)
- humans only reservoirs
44
Q
Clinical features of smallpox?
A
- incubation period: 12 days (7-17 days)
- non-specific prodrome (2-4 days) of fever, myalgias
- rash most prominent on face and extremities (including palms and soles) in contrast to truncal distribution of varicella
- rash scabs at 1-2 wks
- variola rash has synchronous onset (in contrast to varicella - comes in crops)
45
Q
Dx of smallpox?
A
- rash
- hemorrhagic smallpox may be mistaken for meningococcemia or severe acute leukemia
- culture of lesions
- should be obtained by immunized person, place specimen in vacutainer tube, tape juncture of stopper and tube, place in second durable watertight container
- alert lab!
46
Q
Disease course of smallpox?
A
- day 12-14: fever, malaise, non-prod cough, HA, backache, jt pain
- 14-16: papular rash on face and extremities
- 16-18: papular rash w/ vesicular and pustular lesions
- 22-26: crusted lesions
- 28-30: resolving
- 10% will develop malignant disease and die 5-7 days after incubation
47
Q
control of smallpox?
A
- clothing/fomites: decontaminate
- prophylaxis
- pre-exposure: vaccine
- post-exposure: vaccine w/in 4 days or vaccine + VIG (if past 4 days), potential use of cidofovir (antiviral agent)
- isolation: contact + airborne
48
Q
diff b/t variola and varicella?
A
- variola: rash starts on face, lesions all same stage, deep lesions, often palms and soles affected, centrifugal rash, back more than abdomen, mulitloculated vesicles
49
Q
Dx testing for smallpox?
A
- r/o other vesiculating dz
- when in doubt: quarantine/isolate
50
Q
Tx of smallpox?
A
- supportive
- must isolate and immunize contacts
- Cidofovir tx may help
- mortality is age dependent and ranges from 30-95%
51
Q
What is anthrax? 3 clinical forms?
A
- caused by spore forming bacterium, Bacillus anthracis
- human infection typically acquired through contact w/anthrax infected animals or animal products or atypically through intentional exposure
- forms:
cutaneous
inhalational
GI
52
Q
Clinical course of anthrax?
A
- begins as papule, progresses through vesicular stage to depressed black necrotic ulcer (eschar)
- edema, redness, and or necrosis w/o ulceration may occur
- form MC encountered is naturally occurring
-incubation: 1-12 days - case fatality: w/o abx - 20%
w/ abx - 1%
53
Q
DDx of cutaneous anthrax?
A
- spider bite
- Ecthyma gangrenosum
- ulceroglandular tularemia
- plague
- staph or strep cellulitis
- HSV
- cutaneous anthrax is painless
54
Q
Dx testing for cutaneous anthrax?
A
- gram stain, PCR, or culture of vesicular fluid, exudate, or eschar
- blood culture if systemic sxs present
- bx for immunohistoschemistry, esp if person taking antimicrobials
55
Q
Presentation of inhalational (pulm) anthrax?
A
- brief prodrome resembling viral like illness, characterized by myalgia, fatigue, fever, w/ or w/o resp sxs, followed by hypoxia, and dyspnea, often w/ radiographic evidence of mediastinal widening (due to hilar adenopathy)
- meningitis: 50% of pts
56
Q
DDx for inhalational anthrax?
A
- mycoplasmal pneumonia
- legionnaires disease
- Psittacosis
- tularemia
- Q fever
- viral pneumonia
- histoplasmosis
- coccidioidomycosis
- malignancy
57
Q
Presentation of GI anthrax?
A
- abd distress, usually accompanied by bloody vomiting or diarrhea, followed by fever, and signs of septicemia
- GI illness sometimes seen as oropharyngeal ulcerations w/ cervical adenopathy and fever
- develops after ingestion of contaminated, poorly cooked meat
- incubation: 1-7 days
- case fatality: 25-60%
58
Q
DDx of GI anthrax?
A
- acute appendicitis
- ruptured viscus
- diverticulitis
- diseases that cause acute cervical lymphadenitis or acute gastritis
- dysentery
59
Q
Anthrax tx protocol for cases assoc w/ bioterrorist events?
A
- adults: cipro or doxy for 60 days
- kids: cipro or doxy (if older than 8 or weigh over 45 kg - diff dose than if under, also if under 8 - cipro)
