From the Guidelines
The most common etiologies of pyrexia in pediatric patients are viral infections, particularly respiratory viruses like the common cold, influenza, and respiratory syncytial virus (RSV), as well as bacterial infections such as strep throat, urinary tract infections, and ear infections (otitis media) 1.
Key Points
- Viral infections are the most common cause of fever in children, with respiratory viruses being the most frequent culprits 1.
- Bacterial infections, such as strep throat, urinary tract infections, and ear infections, are also common causes of fever in children 1.
- Fever typically develops as part of the body's immune response to infection, with the hypothalamus raising the body's temperature to help fight pathogens.
- For managing fever, acetaminophen (10-15 mg/kg every 4-6 hours, maximum 5 doses in 24 hours) or ibuprofen (5-10 mg/kg every 6-8 hours for children over 6 months) can be used 1.
- Keeping children hydrated is essential during fevers.
- Parents should seek medical attention if a fever exceeds 100.4°F (38°C) in infants under 3 months, persists beyond 3-5 days, rises above 104°F (40°C), or is accompanied by concerning symptoms like lethargy, severe headache, stiff neck, difficulty breathing, or rash 1.
Age-Specific Considerations
- Neonates with UTI have a high incidence of urinary anomalies, with the most common being vesicoureteral reflux (VUR) 1.
- Atypical UTI is considered if the patient is seriously ill or has poor urine flow, an abdominal or bladder mass, elevated creatinine, septicemia, failure to respond with suitable antibiotics within 48 hours, or infection with non–Escherichia coli organisms 1.
- Recurrent UTI is defined as 2 or more episodes of UTI with acute pyelonephritis/upper tract UTI, or 1 episode of UTI with acute pyelonephritis/upper tract UTI plus 1 or more episodes of UTI with cystitis/lower tract UTI, or 3 or more episodes of UTI with cystitis/lower tract UTI 1.
From the Research
Etiologies of Pyrexia in Pediatric Patients
The most common etiologies of pyrexia in pediatric patients include:
- Viral infections, which are self-limited and the most common cause of fever in children 2
- Urinary tract infections (UTIs), which cause more than 90% of serious bacterial illnesses in children, with a higher incidence in younger children 2
- Bacterial infections, such as pneumonia, meningitis, pyelonephritis, or bacteremia, which can be life-threatening and require early identification and treatment 3, 4, 5
- Occult pneumonia, which can be a cause of fever without an apparent source of infection 3
Age-Specific Considerations
The approach to evaluating and managing fever in pediatric patients varies by age:
- Neonates and young infants require a more cautious approach, with hospital admission and systematic complementary investigations, due to a higher risk of serious bacterial infections 2, 5
- Children older than 2 months can be evaluated clinically for signs of bacterial infection, with a focus on identifying toxic signs and risk stratifying for serious bacterial illness 2, 5
Clinical Evaluation
A thorough clinical evaluation is essential in identifying the cause of fever in pediatric patients:
- Hands-off evaluation is crucial for assessing breathing, circulation, and level of interaction 4
- Laboratory markers and clinical prediction rules have limited utility in identifying children at risk for serious infections, emphasizing the importance of clinical examination and prudent use of laboratory tests 4