Febrile infant

Question 1

Fever in infant DDx (6 groups)

Answer 1

(1) Early viral illness: URTI, Gastroenteritis, EBV, adenovirus, CMV, Roseola
(2) Musculoskeletal: Osteomyelitis, Septic arthritis
(3) Skin/Soft Tissue Infection: Adenitis, Cellulitis
(4) Urinary tract infection
(5) Occult bacteremia: S. pneumoniae, E. coli, N. Meningititdis, H. influenzae B, Staph aureus (osteomyelitis, endocarditis)
(6) Non-infectious (Kawasaki, rheumatological, malignancy, periodic fever syndromes)

Question 2

Tx for fever in (i) Newborn under 30 days (6), (ii) Infant 30 – 90 days.

Answer 2

Newborn under 30 days:
“Full septic work-up” (CBC, blood culture, urine culture, lumbar puncture, CXR)
Consider nasopharyngeal aspirate (NPA) for viral studies if respiratory symptoms

Infant 30 – 90 days:
Same as above except LP more “grey zone”
Definitely do LP if irritable, neurologic signs, bulging fontanelle

Question 3

• _______ is the most common cause of fever in children
• Risk of serious bacterial infection is _____ (hi/lo) in healthy, vaccinated children who look generally well
• In most of these children older than 3 months, can give time for illness to “declare itself”: how much time?
• How to advise parents?
• Are non-infectious causes of fever possible?

Answer 3

Viral illness
Low
36 to 48 hrs
Advise parents to re-consult if fever persists or condition deteriorates
Yes

Question 4

Post HiB (H. inf. B) and Prevnar (S. pneumoniae) vaccination, most well-looking febrile children will have a _____ illness. Risk of occult bacteremia/meningitis is _____ in these children

Answer 4

viral

very low

Question 5

If the child looks unwell, is it always necessary to do a full assessment?

Must consider ______ (Dx) if there is a fever without a focus > 48 hours (or sooner, depending on clinical scenario)

Answer 5

Yes, if the child looks unwell, even for less than an hour, must do a full assessment

urinary tract infection

Question 6

What are we really worried about in well-looking 3-to-36-month child with fever? (4)
What are the characteristics/risks assoc with each?

Answer 6

Occult bacteremia (because of Hib vaccine and Prevnar, rate is now 0.25%; 1/3 = E. coli, 1/3 = non-vaccine S. pneumoniae; Risk of persistant bacteremia or focal infection if untreated initially: 1/2000 – 1/3200) - High WBC not sensitive enough to indicate bacteremia

Meningitis (same as bacteremia; Risk of meningitis: 1/8000 – 1/12 000)

Occult Pneumonia (Several studies: CXR can be omitted IF there is no clinical indication of respiratory disease; Check for tachypnea!)

UTI (Fever is often the only presenting symptom;
Overall incidence of UTI in febrile child 2 – 8%; Risk higher in boys < 1 y.o. (especially if uncircumcised), girls, white race, previous UTI, fever > 39°. Bag urine specimen for screening urinalysis but not for culture. In children < 3 m.o., normal U/A does not rule-out UTI.

Question 7

At which point in fever do you check for UTI?

Answer 7

In general, 48 hrs but depends on patient (age, gender, risk factors, symptoms) and clinical setting (ER vs office).