Clinical features and risk factors of plastic bronchitis in Mycoplasma pneumoniae pneumonia children with pulmonary consolidation: a prospective cohort study

Objective: To explore the clinical features and predictive factors of plastic bronchitis (PB) in children with Mycoplasma pneumoniae pneumonia (MPP) and pulmonary consolidation. Methods: Prospective observational study. Children with MPP and lung consolidation who were hospitalized and underwent bronchoscopy and treatment between January 1, 2024, and December 31, 2025, were enrolled as the study subjects. These subjects were divided into a PB group and a non-PB group. Demographic data, laboratory test results, and imaging findings were statistically analyzed to describe their clinical characteristics. Multivariate logistic regression analysis was performed to identify significant risk factors for PB in MPP children with pulmonary consolidation. Results: A total of 65 PB patients and 115 non-PB patients were enrolled. The PB group showed higher rates of respiratory distress, longer hospital stays, longer fever durations, and elevated levels of neutrophil percentage, CRP, PCT, IL-6, LDH, SF, D-dimer, and ALT. Multivariate analysis identified fever duration (OR 6.777), D-dimer (OR 1.020), and LDH (OR 1.643) as significant predictors. Bootstrap validation demonstrated good model stability (corrected AUC 0.971, shrinkage factor 0.866). Optimal cutoffs were ≥7.5 days for fever duration, >0.94 μg/mL for D-dimer, and >400.5 U/L for LDH. Conclusion: Fever duration ≥7.5 days, D-dimer >0.94 μg/mL, and LDH >400.5 U/L are independently associated with PB in MPP children with pulmonary consolidation. These associations support a link between hypercoagulability, excessive inflammation, and PB. Further studies are needed to evaluate whether early anti-inflammatory therapy or bronchoscopic intervention improves clinical outcomes.