Case 10

Question 1

What does an elevated leukocyte count with a left shift suggest?

Answer 1

Bacterial infection!

Question 2

What is on the differential diagnosis for UTI?

Answer 2

Otitis media, Roseola, Bacterial meningitis, Viral meningitis, Urinary tract infection, Pneumonia.

Question 3

What are key findings from testing for a UTI?

Answer 3

Elevated leukocyte count, leukocytes/nitrate in urine.

Question 4

What is the definition of a fever?

Answer 4

Greater than 100.4 deg F (38.0 deg C)

Question 5

What is the definition of bacteremia?

Answer 5

Presence of viable bacteria circulating in blood.

Question 6

What is occult bacteremia?

Answer 6

Bacteremia in a child with high fever.

Question 7

What is sepsis?

Answer 7

Severe systemic illness caused by overwhelming infection of the blood stream by toxin producing bacteria. A diagnosis of sepsis typically requires a positive blood culture.

Question 8

What is fever without a source?

Answer 8

Fever with no apparent focus of infection after careful history and physical examination.

Question 9

What is fever of unknown origin?

Answer 9

Temperature of greater than 38.3 deg C (101 deg F) for at least 2 weeks duration with failure to reach a diagnosis after one week of evaluation.

Question 10

What are meningeal signs?

Answer 10

Neck stiffness (“nuchal rigidity”), Kerning’s sign, Brudzinski’s sign.

Question 11

What is nuchal rigidity?

Answer 11

Involuntary resistance to neck flexion. Clinician flexes patient’s neck forward. In severe cases, increased extensor tone of neck and spine leads to hyperextension of entire spine or “opisthotonus”.

Question 12

What is Kerning’s sign?

Answer 12

Flex patient’s hips and extend knees, and see if patient resists knee extension from this position. Kerning’s sign is positive when patient resits extension.

Question 13

What is Brudzinski’s sign?

Answer 13

Flex supine patient’s neck to see if patient flexes hip and knee. Brudzinski’s sign is positive if patient retracts legs toward the chest.

Question 14

How do the majority of infants younger than 12 mo of age present with bacterial meningitis?

Answer 14

They will not have a positive Kerning’s or Brudzinski’s sign, but can present with a variety of findings including fever, hypothermia, lethargy, respiratory distress, poor feeding, vomiting, diarrhea, seizures, restlessness, irritability, and/or bulging fontanelles. However, if a febrile infant demonstrates a positive Kerning’s or Brudzinski’s sign, you must assume that he or she may have meningitis and perform a lumbar puncture.

Question 15

What are the most likely differential diagnosis for a UTI?

Answer 15

Meningitis, Pneumonia, Occult bacteremia, Roseola

Question 16

What are less likely differential diagnosis for a UTI?

Answer 16

Primary herpes simplex virus (HSV) gingivostomatitis, Otitis media, Vaccine symptoms, Viral upper respiratory tract infections (URI).

Question 17

UTI:

Answer 17

Consider in patients with unexplained fever with a non-focal history and physical examination. Consider degrees of toxicity, dehydration, and ability to retain oral intake. Fussiness and lack of appetite are common associated symptoms.

Question 18

Meningitis:

Answer 18

A worrisome diagnosis that must be considered in any febrile infant, regardless of presence or absence of meningeal signs. The only reliable way to rule out meningitis is with a lumbar puncture. Both viral and bacterial meningitis occur in children.

Question 19

Pneumonia:

Answer 19

Most infants with pneumonia have cough and/or tachypnea, but fever may be the only presenting symptom. Even though chest exam is normal, pneumonia must still be considered.

Question 20

Occult bacteremia:

Answer 20

Bacteremia (usually due to Streptococcus pneumoniae) is possible in a child with high fever and no source of infection on physical examination. Remember, the conjugated pneumococcal vaccine protects against only 13 pneumococcal serotypes.

Question 21

Roseola:

Answer 21

Common viral illness due to human herpes virus 6 (HHV-6) that commonly presents with fever and few other symptoms. When the fever resolves, the child develops a diffuse erythematous maculopapular rash.

Question 22

Primary herpres simplex virus (HSV) gingiovostomatitis:

Answer 22

Usually seen in children 10 mo-3 yr, but is estimated that only 10 to 30 percent of perioral HSV infections are symptomatic. Fever and irritability may be the initial symptoms, but oral lesions that start as vesicles and evolve to ulcerations would be seen shortly after symptoms onset.

Question 23

What are vaccine symptoms?

Answer 23

Typically appear within one to two days after receiving vaccines. The MMR and varicella, however, produce fever 7 to 10 days after being administered in a small number of patients.

Question 24

Viral upper respiratory tract infections (URI):

Answer 24

Presentation may include tachypnea, cough, nasal congestion and coryza. Associated fever is usually low-grade.

Question 25

Chest Xray:

Answer 25

Bacterial pneumonia is possible in an ill-appearing infant with a fever for several days - even in the absence of respiratory symptoms or abnormal pulmonary findings. Some clinicians would consider getting a chest Xray in this setting.

Question 26

Complete blood count:

Answer 26

• An elevated leukocyte count with a “left shift” (an elevation in the number of neutrophils, with an increased number of immature forms [ie bands, myelocytes, or metamyelocytes] suggests a possible bacterial infection.
• Most viral infections are associated with a normal or only slightly elevated leukocyte count and differential

Question 27

Urinalysis (UA):

Answer 27

• A positive nitrite test occurs when a gram-negative bacteria (eg E coli, Klebsiella, and Proteus species) - which can reduce urinary nitrate into nitrite - are present in the urine.
• -A positive nitrite in a UA is highly specific for bacteruria (few false positives), but a negative nitrite has very poor sensitivity (lots of false negatives) for bacteruria of infection.
• Leukocyte esterase test detects esterase released from broken-down leukocytes. A positive test usually indicates presence of leukocytes in urine (pyuria), but pyuria may be seen in a variety of conditions besides UTI.
• -Pyuria is defined as greater than or equal to 5 WBC per high power field in centrifuged urine or greater than or equal to 10 WBC per microliter in uncentrifuged urine.

Question 28

Renal and bladder US:

Answer 28

Study provides information about renal structure and dilations in the collecting system. Useful for establishing presence of vesicoureteral reflux.

Question 29

Voiding cystourethrogram (VCUG):

Answer 29

• This study defines the presence and degree of vesicoureteral reflux, an important risk factor for recurrences of UTIs.
• Should not be performed routinely in children after the first febrile UTI unless there are findings on the renal and bladder ultrasound that suggest high-grade vesicoureteral reflux (VUR). (Most VUR cases are mild and resolve spontaneously.)
• A VCUG is recommended after a second febrile UTI.

Question 30

Radionuclide cystogram:

Answer 30

Although it lacks the detail of a contrast VCUG, a radionuclide cystogram is very accurate in providing information about the presence or absence of VUR, with the advantage of exposing the child to much smaller doses of radiation. It should be performed periodically to follow the course of VUR.

Question 31

When should you hospitalize a child with a UTI?

Answer 31

Admit a patient with suspected UTI or pyelonephritis if she/he is toxic, dehydrated or unable to retain oral intake. Should initiate parenteral antibiotics until culture and sensitivities are known.

Question 32

Empiric intravenous antibiotics for UTI:

Answer 32

Empiric antibiotics for an infant or young child with uncomplicated UTI should cover predominantly enteric gram negative bacilli particularly E. coli (85-90 percent of the time) Infants with severe symptoms should receive intravenous antibiotics.

Question 33

IV antibiotic options for UTI:

Answer 33

Ampicillin, Ampicillin and Gentamicin, Ceftriaxone, Piperacillin/Tazobactam, Ciprofloxacin

Question 34

Ampicillin:

Answer 34

Resistance rates of E. coli are rising so ampicillin alone would not provide adequate coverage. If sensitivity testing shows that the E. coli is sensitive to ampicillin, then ampicillin alone would be effective.

Question 35

Ampicillin and Gentamicin:

Answer 35

Gentamicin has excellent activity against coliform, and the combination is a good option for the empiric treatment of pyelonephritis.

Question 36

Ceftriaxone:

Answer 36

Provides excellent coverage against most gram-negative bacilli (with the major exception being pseudomonas aeruginosa) and an excellent safety profile in children. Can be given once daily. Does not treat enterococcus.

Question 37

Piperacillin/Tazobactam:

Answer 37

Provides excellent coverage against gram neg. bacilli. More expensive than other options and is not optimal therapy for enterococcus either.

Question 38

Ciprofloxacin:

Answer 38

Can be used, but is not the best choice due to cost and potential adverse reactions in children.

Question 39

Oral antibiotics for UTI:

Answer 39

Once patient is tolerating oral intake, pathogen has been identified, and sensitivities are known, patient may complete treatment with an oral antibiotic at home to complete a 10 day course. Options in this situation include: Trimethoprim/sulfamethoxazole (TMP/SMZ), Amoxicillin/Clavulanate (Augmentin), Cephalosporin.

Question 40

Trimethoprim/Sulfamethoxazole (TMP/SMZ):

Answer 40

Inexpensive, well tolerated, and requires only twice-daily dosing. Be alert to rare adverse skin reactions.

Question 41

Amoxicillin/Clavulanate (Augmentin):

Answer 41

Is also effective, but much more expensive than TMP/SMZ.

Question 42

Cephalosporin:

Answer 42

If you wish to use an alternative to TMP/SMZ, a first-generation cephalosporin such as cephalexin is inexpensive and generally well tolerated.

Question 43

Follow up for pyelonephritis:

Answer 43

• If patient is at increased risk for recurrence of UTI, a urinalysis should be performed for any febrile illness without a clearly defined focus.
• Periodic radionucleotide cystogram to follow vesicoureteral reflux (VUR).