Pediatric Primary Care (68 page)

ii.  More than 90 serotypes exist.

d.  
S. aureus.

•  Gram-positive organism; beta-lactamase producer.

•  Produces exoproducts, enzymes, toxins, which contribute to virulence of this organism.

•  Causes confluent bronchopneumonia; often unilateral with areas of hemorrhagic necrosis, cavitation of lung parenchyma, resulting in formation of pneumatocele, empyema, or bronchopulmonary fistula.

e.  
M. pneumoniae.

•  Smallest self-replicating bacterium; lacks cell wall, dependent on host.

•  Binds to ciliated respiratory epithelium and inhibits ciliary action.

•  Airways and areas surrounding are filled with infiltrates.

•  Causes cellular destruction and inflammatory response.

B.  Occurrence.

1.  Acute childhood respiratory infections result in 4.5 million deaths/year.

a.  70% are pneumonia-related deaths.

b.  Bacterial pneumonia less common than viral pneumonia, but has highest mortality.

2.  Viral pneumonia.

a.  Peak attack rate between 2-3 years of life.

b.  More common in fall and winter.

•  Fall: parainfluenza infection causing croup.

•  Winter: RSV and influenza.

•  Viral pneumonia can be complicated by secondary bacterial infection.

3.  Bacterial pneumonia.

a.  More common in children older than 5 years of age.

b.  Occurs in winter to early spring.

c.  Organisms vary according to age of child.

•  
S. pneumoniae.

i.   Children younger than 4 years of age at highest risk.

ii.  Risks factors: male > female, daycare attendance, frequent otitis media (3 times in 6 months), frequent URIs (3 infections in 6 months), prematurity, and previous hospitalization for respiratory disease.

iii. Incubation period varies by serotype but generally short: 1-3 days.

•  
M. pneumoniae.

i.   Leading cause of pneumonia in school-age children, adolescents.

ii.  Occurs year round. Incubation period: 2-3 weeks (range: 1-4 weeks).

iii. Rarely severe enough to warrant hospitalization.

•  
S. aureus:
children younger than 2 years of age at highest risk.

C.  Clinical manifestations.

1.  Viral pneumonia: symptoms variable depending on age.

a.  Onset may be acute or gradual but typically progresses more slowly than bacterial infection.

b.  Nasal congestion and coryza.

c.  Lower respiratory symptoms develop insidiously.

d.  Temperature variable depending on causative agent.

e.  Nontoxic appearing.

f.  History of URI symptoms, rhinitis, cough.

g.  Hoarseness, wheezing, rapid/shallow respirations.

2.  Bacterial pneumonia.

a.
S. pneumoniae.

•  Infants initially.

i.   Mild URI symptoms, unilateral conjunctivitis or OM.

ii.  Abrupt onset of fever to 104°F. May have seizure due to abrupt spike in temperature.

iii. Mild cough; may have diarrhea, vomiting.

•  Infant progress.

i.   Restlessness, apprehension.

ii.  Nasal flaring; rapid, shallow respiration; grunting.

iii. Abdominal distention.

iv. Cough may be absent.

v.  Circumoral cyanosis.

•  Older children and adolescents.

i.   Onset abrupt with rigors followed by temperature 102-104°F.

ii.  Appears ill.

iii. Headache.

iv. Anorexia, nausea, vomiting, diarrhea, abdominal pain.

v.  Dyspnea, pleuritic pain, and cough; cough may be productive.

vi. Alternating restlessness and drowsiness.

3.
M. pneumoniae.

a.  Slow onset.

b.  Malaise, transient arthritic symptoms.

c.  Persistent dry, hacking cough; sore throat often followed by hoarseness.

d.  Low-grade temperature and chills.

e.  May have ear pain.

D.  Physical findings.

1.  Viral pneumonia: symptoms dependent on causative agent and age of child.

a.  Nontoxic appearing.

b.  Tachypnea, cough, diffuse bilateral wheezing, decreased breath sounds throughout lung fields.

c.  Suprasternal, intercostal, substernal retractions.

d.  Cyanosis.

2.  Bacterial pneumonia.

a.
S. pneumoniae.

•  Infants.

i.   Tachypnea; nasal flaring, grunting, retractions; diminished breath sounds; crackles, wheezing.

ii.  Fever.

iii. Tachycardia.

iv. Palpable liver or spleen secondary to abdominal distention.

v.  Air hunger and cyanosis.

•  Older children and adolescents.

i.    Diminished breath sounds over affected area of lung.

ii.   Dullness to percussion over area of consolidation.

iii.  Increased tactile fremitus over area of consolidation.

iv.  Cough productive of bloody or rust-tinged sputum.

v.   Crackles, wheezing, splinting of respirations on affected side.