Risk Factors and Clinical Characteristics of Fulminant Mycoplasma pneumoniae Pneumonia in Children: A Retrospective Case‒Control Study

Background Fulminant Mycoplasma pneumoniae pneumonia (FMPP) represents a life‒threatening progression of typical Mycoplasma pneumoniae pneumonia (MPP) in pediatric patients. This study aimed to identify the risk factors and clinical characteristics associated with FMPP complicated by respiratory failure in children, thereby facilitating early intervention. Methods A retrospective case‒control study involving 66 FMPP children and 217 nonfulminant Mycoplasma pneumoniae pneumonia (NFMPP) children admitted to the Department of Respiratory Medicine and Intensive Care Unit at the Children's Hospital Affiliated with Chongqing Medical University between January and December 2023 was conducted. Cox regression analysis was employed to identify independent risk factors for FMPP. Propensity score matching (PSM) was used to balance risk factor variables, enabling a comparative analysis of clinical characteristics between the FMPP-matched group (n = 62) and the NFMPP-matched group (n = 116). Results (1) Wheezing ( HR  = 1.987, 95% CI : 1.130–3.493, P  = 0.017) and Mycoplasma pneumoniae (MP) load ≥ 1.7×10⁷ copies/mL ( HR  = 1.785, 95% CI : 1.055–3.020, P  = 0.031) and pulmonary consolidation ( HR  = 1.738, 95% CI : 1.037–2.914, P  = 0.036) were identified as independent risk factors for FMPP (all P  < 0.05), whereas concomitant Epstein‒Barr virus (EBV) infection ( HR  = 0.399, 95% CI : 0.185–0.858, P  = 0.019) and β‒lactam treatment duration ≥ 3 days ( HR  = 0.525, 95% CI : 0.303–0.910, P  = 0.022) exhibited protective effects. (2) The FMPP-matched group demonstrated significantly greater incidences of fine crackles, wheezing, atelectasis, and neurological complications (all P  < 0.05). The peripheral blood neutrophil percentage (NEU%), bronchoalveolar lavage fluid NEU%, and liver enzyme levels were markedly elevated, whereas fibrinogen, total protein, albumin, and interferon-γ levels were reduced (all P  < 0.05). Multivariate logistic regression analysis revealed that fine crackles, peripheral blood NEU%, and fibrinogen were independently associated with FMPP. (3) The FMPP-matched group exhibited higher utilization rates of second-line antimycoplasma drugs, β-lactam antibiotics, and glucocorticoids and prolonged hospital stays (all P  < 0.05), yet all patients achieved full recovery without mortality. Conclusion A high MP load and pulmonary consolidation are independent risk factors for FMPP, whereas EBV coinfection and early β-lactam therapy may mitigate this risk. Despite severe systemic inflammation and multiorgan involvement, prompt intervention ensures favourable outcomes.