Pathogen-associated radiological and serum inflammatory findings in pediatric necrotizing pneumonia: a retrospective...

Necrotizing pneumonia (NP) is a severe but relatively uncommon complication of pediatric community-acquired pneumonia. In recent years, increasing clinical attention has been directed toward pediatric NP. This study aimed to characterize the clinical features, chest CT findings, and serum inflammatory markers of pediatric NP, and to examine pathogen-associated differences in imaging patterns and inflammatory profiles.

We retrospectively reviewed 54 children diagnosed with NP between January 2018 and January 2024.Etiologic agents, chest CT findings, and serum inflammatory markers including white blood cell count (WBC), C-reactive protein (CRP), procalcitonin (PCT), lactate dehydrogenase, and D-dimer were analyzed. Pathogen-specific comparisons were restricted to single-pathogen cases to reduce classification bias. Mixed infections were analyzed descriptively and were not reassigned to any single-pathogen category.

Among 54 patients (mean age 6.29 ± 3.68 years), significant age-related differences in pathogen distribution were observed (χ ² = 18.7, p = 0.004). Bacterial pathogens were more common in younger children, whereas Mycoplasma pneumoniae predominated in older age groups. Bacterial prevalence showed a negative association with age (Spearman ρ = -0.82, p < 0.001), while M. pneumoniae prevalence showed a positive association (ρ = 0.79, 95% CI 0.65-0.88). Increasing age was inversely associated with complication severity (OR 0.54 per year increase, 95% CI 0.38-0.72). Identified pathogens included Staphylococcus aureus (n = 8), Streptococcus pneumoniae (n = 5), Mycoplasma pneumoniae (n = 28), adenovirus (n = 1), Haemophilus influenzae (n = 2), and mixed infections (n = 9), most commonly involving M. pneumoniae combined with bacterial or viral pathogens. Chest CT demonstrated consolidation with necrosis and cavitation across pathogen groups. S. aureus infections were associated with higher CRP levels [median 140 (IQR 71.8-200) mg/L] compared with S. pneumoniae [20.5 (8-200) mg/L] and M. pneumoniae [36 (11.5-85.64) mg/L; p < 0.01]. In contrast, M. pneumoniae infections showed lower PCT levels [0.16 (0.15-0.31) ng/L] than bacterial infections. No significant inter-group differences were found in WBC or D-dimer levels. Variations in arterial-phase CT attenuation were descriptively observed across pathogen groups.

In this cohort, pediatric necrotizing pneumonia was associated with age-related variations in pathogen distribution, inflammatory markers, and chest CT characteristics. Elevated CRP levels were observed in Staphylococcus aureus infections, whereas lower PCT levels were noted in Mycoplasma pneumoniae cases. Variations in cavitary patterns were descriptively observed across pathogen groups. Given the retrospective design and the presence of mixed infections, these findings should be interpreted cautiously.