Fever

Question 1

What is the difference between fever and Hyperthermia?

Answer 1

○ Fever = Elevated hypothalamic setpoint for body temperature.

○ Hyperthermia = Normal hypothalamic setpoint but inadequate heat-loss mechanisms.

Question 2

How to adequately confirm fever?

Answer 2

-If < 36 months old: rectal temp > 38.

• If > 36 months old: oral/axillary temp > 37,8 (oral temp is 0.6 degrees less than core/rectal temp).
  ■ Rectal/oral temp may be contraindicated in neutropenia
  ■ Tympanic membrane is close to core temperature

-Always admit to the hospital:
■ Capillary refill time > 3 seconds (“amber” sign)
■ Febrile infants < 3 months with rectal temp > 38℃
■ Febrile infants < 6 months of age who appear ill and have fever > 39℃

Question 3

Describe the different fever patterns and the causative agents of each one.

Answer 3

■Continuous (all day long - Bacterial infection)

■Remitting (daily with > 0.5 degree fluctuations - Endocarditis)

■Intermittent (spikes up for a few hours then goes down - Malaria)

■Undulant (slowly but regularly fluctuates -Brucellosis)

■Periodic (regularly up and down to normal - Autoimmune)

Question 4

Differential diagnosis of Fever ( Not obvious fever causes)

Answer 4

■ Infectious: UTI, EBV, CMV, adenovirus, osteomyelitis, endocarditis,TB.
* They really want us to remember UTI as a possible cause of fever of unknown origin in peds.

■ Inflammatory: incomplete Kawasaki or other vasculitis, JIA, SLE.
● PFAPA: Periodic Fever, Aphthous Stomatitis, Pharyngitis, Adenitis.
Looks like recurrent URI with fever, but follows a steady pattern. Treat with steroids.

■ Oncological: leukemia, lymphoma, neuroblastoma

■ Other: CNS dysfunction, drug fever

Question 5

Fever management

Answer 5

■ Antipyretics:
● **Paracetamol 10-15 mg/kg 4x/day (max 1g/dose)
● Ibuprofen: 10 mg/kg 3-4x/day (max 600/dose)
!! Do NOT use aspirin except in Kawasaki !!

■ External cooling: better if very high fever w/o response to antipyretics , hyperthermia.

■ Always consider dehydration: 10% more fluid needed for every 1 ℃ of fever.

Question 6

Describe the types of febrile seizures in pediatrics

Answer 6

Febrile Seizures:
■ Simple (harmless) febrile seizure: generalized tonic/clonic, lasts < 15 minutes, does not recur in 24 hours.
■ Complicated febrile seizures: focal, last > 15 min, recurs in 24 hours.

Question 7

How to differentiate a febrile seizure from epileptic seizure?
● Febrile seizure has normal neuro exam. Don’t need imaging or
EEG for the first episode unless there are complicated or
recurrent seizures.

Answer 7

● Febrile seizure has normal neuro exam. Don’t need imaging or
EEG for the first episode unless there are complicated or
recurrent seizures.