Fever is not a diagnosis per se. Often the pediatrician’s
first goal is to separate serious causes of fever from minor self-limited
intercurrent illnesses. The most useful tool in the diagnosis of
the etiology of fever is the clinical examination. Many months of
residency and years in clinical practice hone the pediatrician’s
ability to identify the truly sick or “toxic” child.
Perhaps no clinical skill is more important for a pediatrician,
who is often dealing with young children who are not able to communicate
directly, than the ability to identify the seriously ill child.
Listlessness, poor feeding, poor perfusion of the extremities, weakness,
rapid pulse, or lethargy are all clues, as are the more sinister presence
of cyanosis or purpura. Often the signs are subtle and the child
just does “not look right.” Once the child is
identified as being toxic or seriously ill, then appropriate cultures, most
often including urine, blood, and CSF, as well as other laboratory
tests such as a peripheral white blood cell (WBC) count with differential,
electrolytes, and urinalysis, should be obtained. Some clinicians
also use C-reactive protein (CRP) or procalcitonin testing to evaluate
febrile children because these are selectively elevated in children
with bacterial infection.5 For the truly toxic
child and especially for younger children, age-appropriate antibiotics that
can treat sepsis and possible meningitis should be started. In most
areas of the country, this must now include coverage against resistant
gram-positive organisms through the inclusion of vancomycin. For
the child that is less seriously ill, a more measured clinical evaluation
is warranted. Such an evaluation should include history as well
a physical examination to delineate the patient’s symptoms
and clinical course. Knowledge of the most common infectious etiologies
in a given age group is also important. Pharyngitis, upper respiratory infection,
otitis media, gastroenteritis, and bronchiolitis are all common
causes of fever and can often be diagnosed by review of the history
and physical examination alone. Similarly, varicella, roseola, and
scarlet fever, as well as Kawasaki disease, can also be diagnosed
on the basis of physical examination. For other entities, it may
not be possible to identify a specific focus of infection. For children
without a readily identifiable focus, the most common etiology is
a self-limited viral illness. Two common causes of fever in infants
and children are urinary tract infection and occult bacteremia.
Urinary tract infection is discussed further in Chapter 238.
Prolonged fever of unknown origin is discussed in Chapter 228,
and fever in the immunocompromised child is discussed in Chapter 229. Occult bacteremia is discussed below. An algorithm summarizing
the evaluation and management of febrile infants and children is
shown in Figure 227-1.