6. Fever without a Source

Question 1

What’s the definitive measurement technique for temperature? (2)

Answer 1

• rectal (< age 5 yr)
• oral (> age 5 yr)

Question 2

Name: Normal temperature ranges

• Rectal
• Tympanic
• Oral
• Axillary

Answer 2

• Rectal: 36.6°C–38°C
• Tympanic: 35.8°C –38°C
• Oral: 35.5°C–37.5°C
• Axillary: 34.7°C–37.3°C

Question 3

Describe: Pyrogens (2)

Answer 3

• Apyrogen is a substance the produces feve
• that is, a portion of viruses or bacteria (lipopolysaccharide) or components of the innate and active immune system (complement, antigen–antibody complexes).

Question 4

Describe physiopathology of fever (5)

Answer 4

• Fever is an important physiologic response to invading pathogens.
• The thermoregulatory center is in the hypothalamus, and is responsible for maintaining the body’s temperature within a specific range.
• The production of heat occurs by increased cellular metabolism, often by involuntary shivering of skeletal muscle.
• The specific range targeted by the thermoregulatory center in the CNS can be changed by the presence of cytokines and pyrogens, resulting in activation of body mechanisms to create heat, and the production of fever
• Importantly, the increase in the set point of the thermoregulatory center is mediated by PGE2—the target of antipyretic agents, such as NSAIDs and acetaminophen.

Question 5

Describe: Mechanism of Antipyretic Agents (3)

Answer 5

Synthesis of PGE2 depends on COX; therefore, antipyretics = COX inhibitors

• Nonsteroidal anti-inflammatory agents (indomethacin, ibuprofen): COX inhibitors and excellent antipyretics
• Acetaminophen: poor COX inhibitor in peripheral tissue but oxidized in CNS to a form that inhibits COX
• Glucocorticoids reduce PGE2 synthesis by inhibiting the activity of phospholipase A2 (preventing release of arachidonic acid) and block the transcription of mRNA for pyrogenic cytokines.

Question 6

Should aspirin be used to treat acute febrile illness in children?

Answer 6

• No, Aspirin should not be used to treat acute febrile illness in children.
• ASA ingestion by children with varicella or influenza has been associated with Reye syndrome.
• Reye syndrome is characterized by encephalopathy and fatty degeneration of the liver and is associated with significant morbidity and mortality.

Question 7

Name Causes of fever by duration (Figure)

Answer 7

Question 8

Describe HX: Fever in children (6)

Answer 8

• ID: age (if neonate or infant, exact number of days)
• Fever Hx: exact number of hours per days, clarify mechanism of measurement and how high the fever is, if fever is persistent or episodic, response to antipyretics (and which antipyretics used, dosage, frequency), previous fevers, precipitating factors (e.g., drugs), associated symptoms (e.g., salmon-pink rash—JIA)
• Review of systems: weight loss, night sweats, energy level, appetite, fluid intake (exactly how much and how often), rashes, swollen joints, focus of infection (cough, coryza, fluid from ears, etc.), dysuria (or anuria), abdo pain, emesis, change in bowel movements (diarrhea ± blood, mucous), abnormal vaginal/penile discharge, headache, behavior changes, gait changes, cough, shortness of breath
• PMHx: pregnancy Hx (if neonate or infant—GBS status, duration of rupture of membranes, prophylactic antibiotics, signs of chorioamnionitis, complications of pregnancy and delivery, postnatal course), feeding Hx if neonate/infant (is baby waking to feed vs. lethargic, voiding/stooling normal amounts), chronic illnesses, hospitalizations, surgeries, development, recent medications (antibiotics, gluco- corticoids, immune suppressants), immunizations, allergies
• SHx: recent travel/camping/boating, exposure to family members with travel Hx, known TB contacts, if adolescent—always take HEADDSSS Hx
• FHx: recent travel or infections in family members, Hx of autoimmune conditions, or malignancy. FHx of immune deficiencies, early neonatal deaths, genetic conditions.

Question 9

Describe physical exam: Fever in children (8)

Answer 9

• Vitals: if fever present, note where it was taken, BP (check against normal value charts for gender, age, and height), HR, RR (tachypnea can be a sensitive indicator for pneumonia, but may also be present with fever), oxygen saturation
• General appearance: toxic versus nontoxic, level of consciousness, color, level of distress
• HEENT: fontanelle (infant), lymphadenopathy, conjunctivitis (bilateral vs. unilateral, purulent vs. nonpurulent), rash (the rash of measles begins on the head and moves downwards), erythema or bulge behind tympanic membrane, ear displacement or any focal area of erythema (i.e., retroauricular), oropharynx (posterior oropharynx—erythema, exudate, tonsillar hypertrophy, palate—petechiae, buccal mucosal—Koplik spots), neck (nuchal rigidity, Kernig sign, Brudzinki sign)
• CVS: murmur, extra heart sounds, muffled heart sounds, perfusion
• Respiratory: work of breathing, asymmetric movement of chest, adventitious sounds (stridor, wheeze, crackles), decreased air entry, dullness to percussion
• Abdo: increased bowel sounds, distension, pain, masses, hepatosplenomegaly
• MSK: deformities, localized tenderness, erythematous/swollen joints or extremities (Kawasaki disease—edema of hands/feet), decreased ROM
• Skin: rash (viral exanthem, petechiae, maculopapular), lesions (check entire body, including oropharynx, palms of hands/feet), localized erythema

Question 10

Name: Clinical Signs of Meningitis (3)

Answer 10

• Nuchalrigidity
• Kernig sign—when upper leg flexed at 90 degrees, extension of leg is painful.
• Brudzinki’s sign—forced flexion of head results in involuntary flexion of hips.

Question 11

Name: Kawasaki Disease Criteria (5)

Answer 11

Fever for at least 5 d, and the presence of at least 4 of the 5 following signs:

• Bilateral, non purulent conjunctivitis
• Mouth/oropharyngeal changes— strawberry tongue, dry/cracked very- thematous lips
• Polymorphous rash
• Extremity changes—edema of hands and feet, in later stages can see desquamation (peeling) of periungual skin
• Unilateral cervical adenopathy, > 1.5 cm

Question 12

Describe investigations: Fever (7)

Answer 12

• Depending on your Hx and clinical exam, investigations may not be indicated (if the child appears well, you suspect viral infection, and the family has good follow-up for any further concerns).

Investigations to consider include

• Laboratory: CBC ± blood culture, electrolytes, liver enzymes, creatinine, urea, ESR, CRP
• Urine: urinalysis (usually a urine dip) ± culture, if indicated
• Stool: culture (bacterial), electron microscopy (viruses), O&P
• CSF: LP indicated in neonates with fever and the majority of infants < 90 d of age with fever. Consider in other children if toxic in appearance, altered level of consciousness, etc.
• Other: throat swab (bacterial pharyngitis), joint aspiration (if swollen, erythematous joint—in consultation with rheumatologist or orthopedics)
• Imaging: CXR (if respiratory symptoms or increased WOB), abdo XR (if signs of obstruction or concerned for pneumoperitoneum), joint or bone XR (if suspect osteomyelitis—MRI is best test)

Question 13

Describe: Approach to fever without a source ()

Answer 13

Question 14

Name: Full Septic Workup (5)

Answer 14

• Blood culture
• Urine culture
• Lumbar puncture— CSF culture
• ± CXR in presence of respiratory symptoms
• Note: also consider nasopharyngeal swab for viruses, throat swab, and stool for virology/bacteriology/ parasitology, if indicated based on symptoms/exposure Hx

Question 15

Name: Rochester Criteria for Infants at Low Risk of Serious Bacterial Illness (5)

Answer 15

1. Previously healthy term infant without perinatal complications and no previous antibiotic treatment
2. Normal physical exam findings
3. White blood cell count: 5,000 to 15,000 cells/mm3
4. Band count: < 1,500 cells/mm3
5. Urinalysis:< 10 white blood cells/HPF in centrifuged catheterized specimen

• A partial septic workup can be considered in febrile infants 1 to 3 mo of age who are at low risk of having a serious bacterial illness.

Question 16

Name: Signs of Sepsis on Exam (5)

Answer 16

• ear y: peripheral vasodilation (tachycardia, bounding pulses, warm extremities, adequate capillaryre rell)
• late: poor distal perfusion (cool extremities, delayed capillary refill, altered mental status, ↓ urine output)
• Septic shock (inadequate organ function/perfusion)
• Altered level of consciousness Hypoxemia
• Oliguria (< 0.5 mL/kg/h)

Question 17

Describe: Educating Parents about fever (3)

Answer 17

• It is important to inform parents that fever is the body’s normal response to infection, and is not usually harmful.
• Treatment of fever should be di- rected at the child’s symptoms (↓ energy, ↑ myalgias, etc.) and not at the absolute value of the fever.
• If the fever is consistently present for > 2 d, the child should be evaluated by a physician for a source that may require treatment (i.e., if antibiotic therapy is warranted)

Question 18

Describe DX: Fever (3)

Answer 18

• The diagnostic evaluation of a child with fever without a source can be categorized by age.
• However, there are other important factors to consider as well—such as whether the child appears unwell (toxic vs. nontoxic), the family’s reliability or ability to seek further care (i.e., access to transportation), or the concern of the family (parents know their children best!).
• For infants between 1 to 3 mo of age, the extent of the diagnostic evaluation performed is often dependent on these other factors.

Question 19

Describe management: Fever (5)

Answer 19

• Management will vary depending on the etiology of the fever.
• If the fever is likely due to a viral infection, the family can be counseled about the role and appropriate management of fever.
• For example, the recommended dosage of acetaminophen is 10 to 15 mg/kg given every 4 h (to a maximum of 75 mg/kg/d or 4 g, whichever is less),
• and ibuprofen is 10 mg/kg given every 6 h (to a maximum of 40 mg/kg/d).
• For common organisms and empiric antibiotic options by age-group, please see Table 18.10. For common organisms and antibiotic options by type of infection, please see Table 18.11; however, it is important to consider local resistance patterns when selecting antimicrobial therapy. If a serious bacterial infection or sepsis is suspected, the patient should be initially resuscitated using the management guidelines below, and treatment initiated prior to transfer to an admitting facility.

Question 20

Name Jones Criteria for Acute Rheumatic Fever (2)

Answer 20

• Dx: 2 major criteria or 1 major + 2 minor + evidence of recent GAS infection (positive culture or rising titers)
  
  • MAJOR: “SPACE”
    
    • Subcutaneous nodules, Polyarthritis, Arthritis, Carditis, erythema marginatum
  • MINOR: “ LEAF”
    
    • long PR interval, elevated acute- phase reactants, Arthralgia, Fever

Question 21

Describe: GAS Pharyngitis (4)

Answer 21

• GAS accounts for 15% to 30% of pharyngitis in school-aged children.
• Dx: by throat culture (gold standard) or rapid antigen detection test
• Treatment: Penicillin VK or Amoxicillin solution. If allergic, cephalosporins or macrolides may be used.
• Must be treated to prevent suppurative and nonsuppurative complications (see Clinical Box, Jones Criteria for Acute Rheumatic Fever)

Question 22

Describe common organisms and empiric treatment options by age: Neonate (0–28 d)

Answer 22

• Likely organism:
  
  • Common Group: B Streptococcus, E. coli
  • Other: S. aureus, Listeria monocytogenes, Enterococcus, herpes simplex virus, gram-negative organisms
• Empiric tx: Ampicillin + cefotaxime or ampicillin + aminoglycoside. Consider acyclovir

Question 23

Describe common organisms and empiric treatment options by age: Infant (29–90 d)

Answer 23

• Likely organism:
  
  • Common: S. pneumoniae, H. influenzae, N. meningitidis
  • other: Group B Streptococcus, E. coli, S. aureus, Enterococcus, Listeria monocytogenes, Pseudomonas sp., other gram-negative organisms
• Empiric tx:
  
  • Ampicillin + cefotaxime
  • Consider vancomycin for suspected meningitis

Question 24

Describe common organisms and empiric treatment options by age: > 3 mo

Answer 24

• Likely organism:
  
  • S. pneumonia, H. influenza, N. meningitidis, S. aureus
• Empiric tx:
  
  • Ceftriaxone ± vancomycin

Question 25

Name common bacterial pathogen(s) and empiric ATB tx: Meningitis

Answer 25

• Common bacterial pathogen(s): N. meningitides, S. pneumoniae, HiB (now rare)
• Empiric ATB tx: Third-generation cephalosporin (crosses BBB) + vancomycin

Question 26

Name common bacterial pathogen(s) and empiric ATB tx: Upper respiratory tract infection

Answer 26

• Common bacterial pathogen(s):
  
  • Pharyngitis: GABHS
  • Acute otitis media: S. pneumoniae, NTHI, M. catarrhalis
• Empiric ATB tx:
  
  • Penicillin, Amoxicillin

Question 27

Name common bacterial pathogen(s) and empiric ATB tx: Pneumonia (1)

Answer 27

• Common bacterial pathogen(s): S. pneumoniae, GABHS; atypicals
• Empiric ATB tx:
  
  • Ampicillin/amoxicillin or cefuroxime; macrolides

Question 28

Name common bacterial pathogen(s) and empiric ATB tx: UTI

Answer 28

• Common bacterial pathogen(s): E. coli ( rs: Klebsiella, Enterococcus, Proteus, Serratia)
• Empiric ATB tx: TMP-SMX; cephalexin or cefixime

Question 29

Name common bacterial pathogen(s) and empiric ATB tx: Septic arthritis

Answer 29

• Common bacterial pathogen(s): S. aureus, Strep
• Empiric ATB tx: Cloxacillin

Question 30

Name common bacterial pathogen(s) and empiric ATB tx: Endocarditis

Answer 30

• Common bacterial pathogen(s): S. viridans (native valve)
• Empiric ATB tx: IV penicillin G or ceftriaxone + gentamicin

Question 31

Name common bacterial pathogen(s) and empiric ATB tx:

Answer 31

• Common bacterial pathogen(s):
• Empiric ATB tx:

Question 32

Name common bacterial pathogen(s) and empiric ATB tx:

Answer 32

• Common bacterial pathogen(s):
• Empiric ATB tx:

Question 33

Name common bacterial pathogen(s) and empiric ATB tx:

Answer 33

• Common bacterial pathogen(s):
• Empiric ATB tx:

Question 35

Name ATBs contraindicated in children (2)

Answer 35

• Fluoroquinolones: impair bone/cartilage growth
• Tetracyclines: Staining of teeth, damage growing cartilage

Question 36

Name complications: Influenza (7)

Answer 36

• bacterial pneumonia
• Reye syndrome
• encephalopathy
• myositis
• febrile seizures
• dehydration
• and worsening of chronic medical conditions (asthma, chronic pulmonary disease)

Question 37

Describe prophylaxis: Influenza (2)

Answer 37

• Annual immunization recommended for children with chronic diseases and their contacts, and for all children between 6 mo and 2 yr of age
• Antiviral drugs in patients not immunized or who may have suboptimal response to vaccine (chemoprophylaxis, see below)

Question 38

Describe tx: Influenza (3)

Answer 38

• May be useful to reduce the severity and duration of symptoms if Dx confirmed by nasopharyngeal swab or viral culture.
• Indications:
  
  • ↑ Risk of severe or complicated influenza due to underlying chronic illness (± vaccination)
  • Healthy children with severe illness requiring hospitalization
• Antiviral medications:
  
  • Neuraminidase inhibitors—decrease release of influenza A and B from infected cells (oseltamivir [Tamiflu] and zanamivir)
  • Tricyclic amines—inhibit replication of influenza A (amantadine and rimantadine)