Case 10: infant- Fever Flashcards
diffdx fever in an infant
- vaccinations (w/in 24-48h) = esp. live vaccines; MMR/varicella = 7-10d fever post-vaccine
viral syndrome
- URI
- meningitis
- acute gastroenteritis
- HSV gingivostomatitis
- roseola
- fifth disease
SBI
- UTI
- meningitis
- sepsis
- pneumonia
- bacterial gastroenteritis
- osteomyelitis
- septic arthritis
- soft tissue infection
signs of meningitis in infants (<12mo)
- fever
- hypothermia
- bulging fontanelles
- lethargy
- irritability
- restlessness
- paroxysmal crying (crying when picked up)
- poor feeding
- vomiting and/or diarrhea
- nuchal rigidity
- opisthotonos = icreased extensor tone of neck and spine –> hyperextension of entire spine
+/- Kernig / brudzinski’s sign (usually >12mo)
occult bacteremia
- define:
- epidemiology
- labs
define:
“occult bacteremia” = only a little fussy + bacteremia ==> low risk of SBI
“ septic” = appears ill, toxic + bacteremia ==> high risk of SBI; medical emergency
epidemiology of occult bacteremia
- use of vaccines = decreased risk of Strep pneumo, H inflluenza
- other causes of occult bacteremia = Neisseria meningitidis, Salmonella enteritidis
LABS
- if immunized –> less likely true high WBC
- if other RFs for SBI –> supported by high WBC, left-shift (bands)
when to use antibiotics and what kind, if you are worried that this kid has a serious bacterial illness (SBI) from a UTI
1) prophylactic antibiotics ==> can reduce UTI recurrence (esp. in kids with veisucoureteral reflux), but does NOT prevent renal scarring
2) ORAL > IV antibiotics
- in most cases
3) IV > oral
- if pts are toxic
- if unable to retain oral meds
- if concerned about compliance with oral meds
define: Kernig’s sign
resistance to extension of the knee. (d/t to pain)
define: Brudzinski’s sign
flexion of the hip and knee in response to flexion of the neck by the examiner
diffdx of infant with a fever
- sxs:
- signs:
- RFs:
0) VACCINE RXN = within 1-2d after
1) UTI
- sxs: fever; fussiness, lack of appetite; no focal signs
- signs: temp >39, >/= 24h without a source
- RFs: uncircumscribed male <6mo; female < 24mo
2) PNEUMONIA
- sxs: cough, tachypnea, fever, rales, low SaO2
- RFs: non-immunized
3) SEPSIS / BACTEREMIA =systemic response to infectious agent –> inflammation throughout body –> vasodilation, leukocyte accumulation, increased capillary permeability
- sxs: hypo/hyperthermia; “toxic;”
- signs:
1) early = tachycardia
2) late = end-organ hypoperfusion; delayed capillary refill; low BP, AMS, organ failure
4) OCCULT BACTEREMIA
- sxs: positive blood culture in a well-appearing child
- low risk of serious bacterial illness
5) BACTERIAL MENINGITIS (sxs of bacterial»_space; viral) ==> S. pneumoniae; N. meningitidis
- signs: bulging fontanelle, nuchal rigidity / other signs of meningismus
6) VIRAL MENINGITIS ==>enterovirus
- sxs: less severe v. bacterial; fever; loose stools, rashes, URI
7) ROSEOLA = viral illness (HHV-6)
- sxs: (1) high fever for 3-5d; (2) rash for 1-4d
- RFs: kids <2y
8) PRIMARY HSV GINGIVOSTOMATITIS
- sxs: (1) fever, irritability, (2) oral lesions = vesicles –> ulcerations
- RFs: kids 10mo-3yo
9) OTITIS MEDIA
- sxs: poor mobility, mild bulging of tympanic membrane (+/- red TM)
10) VIRAL URI
- congestion, cough, rhinorrhea, coryza
w/up for fever without a source
- UA, urine culture (catheterized or suprapubic catheterization)
- CBC with differential
- blood culture = for child that is ill-appearing, pale, inconsolable
- lumbar puncture = for child that is ill-appearing, pale, inconsolable
IF NEEDED:
- (diarrhea) stool guaiac, fecal leukocytes –> stool cultures
- (lower respiratory tract disease, WBC > 20K) = CXR
- rapid test for viral respiraotry pathogens
- inflammatory markers = CRP, procalcitonin, IL-6
in an immunized child with no respiratory findings and looking well, is a WBC necessary to r/out a pneumonia?
NO. because not likely to be a pneumonia in the first place
in an immunized child with no respiratory findings and looking well, is a CBC/WBC necessary to r/out a pneumonia?
NO. because not likely to be a pneumonia in the first place
in a fully immunized child (3-36mo) who appears well, normal fontanelle, no nuchal rigidity / other signs of meningismus, is a LP necessary to r/out a meningitis?
NO
but you do need in <3mo –> b/c young infants CAN lack these signs and still be septic.
in a fully immunized child (3-36mo) who appears well, normal fontanelle, no nuchal rigidity / other signs of meningismus, is a LP necessary to r/out a meningitis?
NO
but you do need in <3mo –> b/c young infants CAN lack these signs and still be septic.
most likely cause of serious bacterial illness
UTI
18mo kid comes in only with a sore throat. do you perform a throat culture / rapid strep test?
NO
- strep pharygitis is unusual in young children
- acute rheumatic fever rarely occurs in children <3yo
describe how to interpret a UA for UTI
positive UA = positive nitrite, positive leukocyte esterase
- positive pyuria (WBCs in urine): >5 WBCs per HPF
- positive nitrite (reduced urinary nitrate into nitrite) ==> presence of bacteria in urine
- positive leukocyte esterase test (presence of WBC releasing esterases released from broken-down leukocytes)
you think a kid 2yo has a UTI, but the UA is negative for nitrites. how do you interpret this?
negative nitrite has poor sensitivity (lots of false negatives)
b/c young infants have little control over urination; it takes ~4h for bacteria in urine to reduce nitrite.
so can have UTI, but not detect nitrite
what are the follow-up studies for an episode of pyelonephritis
1) US of kidneys and bladder == renal structure, dilatations in collecting systems
==> for first febrile UTI, @ completion of Abx course (or earlier if needed)
2) Renal technetium scan == evidence of pyelonephritis
==> for those not responding well to treatment
3) Voiding cystourethrogram (VCUG) == presence of vesicoureteral reflux (VUR)
==> esp. for US findings of high-grade VUR (== hydronephrosis)
==> after 2nd febrile UTI
common cause of UTI in young infants
high-grade VUR (== hydronephrosis)
Management of a young, febrile child
NOT empiric treatment with prophylactic Abx==> b/c most who are immunized will not develop bacteremia
w/up for source of infection
Management of pyelonephritis
most common cause of pyelo = E. coli; Klebsiella, Proteus, enterococcus
PARENTERAL ABX
1) Ampicillin/gentamicin ==> E. coli, enterococci
2) Ceftriaxone ==> GNR
* * do NOT give at same time as Ca-containing meds –> Ca precipitates in lungs, kidneys
3) Piperacillin/tazobactam ==> GNR, Pseudomonas
4) Ciprofloxacin ==> complicated UTI with resistant organisms; children > 1yo
ORAL ABX
1) Cephalexin = best
2) Ciprofloxacin (same concentration in IV v. oral) - concerns about s/e profile (articular cartilage)
3) Amoxicillin/clavulanate n- concerns about s/e profile (skin, GI)
for UTI/cystitis, not pyelo
1) Nitrofurantoin = therapeutic level only in urine, NOT in blood
which do NOT use d/t resistance
- Sulfisoxazole
what antibiotic can you not give with Ca-containing medications
Ceftriaxone
Ceftriaxone + Ca-containing meds –> Ca precipitates in lungs, kidneys
define: fever without source
v. fever of unknown origin
fever without source = complete hx has been obtained and detailed physical exam performed, with no identified source for fever (usually viral)
fever of unknown origin = temperature greater than 38.3 C (101 F) for at least two weeks’ duration with failure to reach a diagnosis after one week of evaluation
management guidelines for fever without a source
in a fully immunized child (esp. PCV7), decreased likelihood of bacteremia (esp if WBC < 15,000) –>so no need to treat prophylactically
- almost all children now with elevated WBC represent false positives for bacteremia
1) discuss concerns with parents
2) close & careful follow up
3) document findings
ONLY TREAT PROPHYLATICALLY with ABx if
- develop more serious sxs
Holly is a previously well 6-month-old girl with a 2-day history of high fever, fussiness, and poor appetite. On exam she is tachycardic, pale, and inconsolable but without apparent source for her fever.
Of the following, which do you think are the more likely causes of Holly’s illness?
Multiple Choice Answer: A Bacterial meningitis B Herpes simplex virus gingivostomatitis C Occult bacteremia D Otitis media E Pneumonia F Roseola (Exanthem subitum) G Sepsis/bacteremia H Urinary tract infection I Vaccine reaction J Viral meningitis K Viral upper respiratory tract infection
bacterial meningitis roseola sepsis/bacteremia UTI viral meningitis
- physical exam rules out otitis media, HSV gingivostomatitis
- too ill to have occult bacteremia
- fully immunized without respiratory sxs = less likely pneumonia, viral URI
- too far out to be from vaccines (only MMR, given >6mo would lead to rsn this late)