Clinical and laboratory features of children with community-acquired pneumonia are associated with distinct radiographic presentations.

Chest radiographs from children with community-acquired pneumonia (CAP) were categorized into three distinct presentations and each presentation was correlated to clinical and laboratory findings. Children < 59 months with CAP presenting to pediatric emergency rooms during two years were enrolled prospectively in eight centers across Europe. Clinical and laboratory data were documented and radiographs obtained from patients. Of the 1107 enrolled patients, radiographs were characterized as 74.9% alveolar CAP, 8.9% non-alveolar CAP, and 16.3% clinical CAP. Alveolar CAP patients had significantly higher rates of fever (90.7%), vomiting (27.6%), and abdominal pain (18.6%), while non-alveolar CAP patients presented more with cough (96.9%). A model using independent parameters that characterize alveolar, non-alveolar, and clinical CAP demonstrated that alveolar CAP patients were significantly older (OR = 1.02) and had significantly lower oxygen saturation than non-alveolar CAP patients (OR = 0.54). Alveolar CAP patients had significantly higher mean WBC (17,760 ± 8539.68 cells/mm3) and ANC (11.5 ± 7.5 cells/mm3) than patients categorized as non-alveolar CAP (WBC 15,160 ± 5996 cells/mm3, ANC 9.2 ± 5.1 cells/mm3) and clinical CAP (WBC 13,180 ± 5892, ANC 7.3 ± 4.7). CONCLUSION: Alveolar CAP, non-alveolar CAP, and clinical CAP are distinct entities differing not only by chest radiographic appearance but also in clinical and laboratory characteristics. Alveolar CAP has unique characteristics, which suggest association with bacterial etiology. TRIAL REGISTRATION: Trial number 3075 (Soroka Hospital, Israel) What is Known: • Community-acquired pneumonia in children is diagnosed based on clinical and radiological definitions. • Radiological criteria were standardized by WHO-SICR and have been utilized in vaccine studies. What is New: • Correlation between the WHO-SICR radiological definitions and clinical and laboratory parameters has not been studied. • Using the WHO-SICR radiological definitions for alveolar community-acquired pneumonia (CAP) and non-alveolar CAP and the study definition for clinical CAP, it was found that the groups are distinct, differing clinically and in laboratory parameters.