Pediatric emergency medicine trisk 2280 2280

The most common causes of community-acquired pneumonia are viral infections.
Beyond the neonatal period, the most common bacterial cause is pneumococcus.
Less common, but more severe bacterial causes of pneumonia include S. aureus and GAS.
While chest radiography can be useful to evaluate for complications of pneumonia, such as empyema
or lung abscess, radiographic appearance alone is not useful for differentiating viral from bacterial
etiologies.
Current Evidence
The most common causes of pneumonia in different age groups are listed in Table 94.13 . The most common
causes are viral. Among the bacteria, S. pneumoniae predominates at every age beyond the newborn period. S.
aureus causes a severe, rapidly progressive but uncommon pneumonia in young children; 60% of these infections
occur in the first year of life. GAS is also uncommon but may also be severe. Anaerobic bacteria play a role
primarily following aspiration.
TABLE 94.13
MOST COMMON CAUSES OF PNEUMONIA BY AGE
Age

Viral

Pyogenic bacteria

Other

<3 wks

CMV
RSV
hMPV
HSV
Rubella

Group B streptococcus (S. agalactiae )

Gram-negative enterics (E. coli, Klebsiella )
S. pneumoniae
S. aureus, especially in hospitalized
neonates

Bordetella pertussis
Chlamydia trachomatis
Mycobacterium hominis
Treponema pallidum (syphilis)
Ureaplasma urealyticum

3 wks–3
mo

RSV
hMPV
Parainfluenza
Adenovirus
Influenza
RSV
hMPV
Parainfluenza
Adenovirus
Influenza
hMPV
Influenza
Adenovirus

S. pneumoniae
S. aureus

H. influenzae (nontypeable)

Bordetella pertussis
Chlamydia trachomatis

S. pneumoniae
S. pyogenes (group A streptococcus)
S. aureus

Mycoplasma pneumoniae
Chlamydia pneumoniae
Mycobacterium tuberculosis

S. pneumoniae
S. pyogenes (group A streptococcus)
S. aureus

Mycoplasma pneumoniae
Chlamydia pneumoniae
Mycobacterium tuberculosis

3 mo–5
yrs

5–18 yrs

CMV, cytomegalovirus; RSV, respiratory syncytial virus; hMPV, human metapneumovirus; HSV, herpes simplex virus.

Goals of Treatment
Early recognition of children with respiratory distress and findings consistent with bacterial pneumonia is ideal.

The clinical team should be cognizant of indications for imaging other than chest radiographs, as well as what
radiographic patterns may be more consistent with certain pathogens. Clinical outcomes for patients with
pneumonia include appropriate antibiotic utilization and indications for admission for treatment.
Clinical Considerations
Clinical recognition: Bacterial pneumonia generally has an abrupt onset with fever, often accompanied by chills. A
cough is a common but nonspecific complaint. Younger children may have decreased activity level or appetite.
Pleuritic chest pain may be seen. The most common examination finding other than pyrexia is tachypnea. The
observation of the child at rest before the examination often provides the key to the diagnosis of pneumonia. A
hasty effort at auscultation that disturbs the quiet infant obscures this finding. Grunting respirations in a young