Make the Diagnosis: Pneumonia, Infant and Child
Given cough or respiratory symptoms, the prevalence of pneumonia is approximately 15% to 35%. However, prevalence of pneumonia may be lower during RSV season. Prevalence may also be slightly higher in children younger than 3 years.
Population for Whom Pediatric Pneumonia Should Be Considered
Patients with symptoms of acute respiratory illness, primarily cough, respiratory distress, or tachypnea, need to have pneumonia considered as part of the differential diagnosis.
Detecting the Likelihood of Pediatric Pneumonia
The individual clinical symptoms used to identify patients with pneumonia have relatively poor predictive value. Tachypnea, respiratory distress, and abnormal lung sounds (rales) have the best operating characteristics, although the data from different sources conflict on their significance (Table 41-6). Additionally, the clinician's overall clinical judgment/impression may have operating characteristics similar to individual signs and symptoms in diagnosing pneumonia, but the overall judgment is admittedly a complex and difficult “finding” to quantify. To date, there are no randomized controlled studies to validate any proposed multivariate model for predicting pneumonia.
Table 41-6Likelihood Ratios of Symptoms and Signs for Pediatric Pneumonia |Favorite Table|Download (.pdf) Table 41-6 Likelihood Ratios of Symptoms and Signs for Pediatric Pneumonia
|Symptom or Sign ||LR+ (95% CI) or Range ||LR– (95% CI) or Range |
|Grunting among children with wheezing, < 18 mo ||2.8 (1.6-4.4) ||0.7 (0.55-0.89) |
|Grunting ||2.8-3.2 ||0.70-0.86 |
|Retractions ||2.7 (1.1-6.9) ||0.97 (0.93-1.0) |
|Rales ||1.8-15 ||0.69-0.86 |
|Tachypnea (use WHO age-adjusted criteria) ||1.6-8.0 ||0.32-0.91 |
|Fever ||1.2-1.5 ||0.17-0.30 |
The reference standard for pediatric pneumonia remains the chest radiograph. Sputum production is not a frequent finding in pediatric patients, and therefore, isolation of sputum for microbiologic correlation with pneumonia remains both difficult and impractical. The development of rapid antigen detection of common viruses such as RSV and influenza will help the clinician rule out causes of respiratory symptoms other than bacterial pneumonia. As of now, there is still no way to differentiate bacterial vs viral pneumonia by chest radiograph.
Original Article: Does This Infant Have Pneumonia?
A mother brings her 8-month-old infant to your office in midwinter with a cough. She reports that the illness began 4 days ago with a runny nose. Two days ago, the baby developed a fever. Now the baby's symptoms are getting worse. The baby has become more irritable, is eating less, and seems to be having more difficulty breathing. This is the third child you have treated today with a cough. While the first two children were treated for acute upper respiratory tract infections, you wonder if the findings in this infant suggest pneumonia.