The clinical characteristics and risk factors for necrotizing pneumonia caused by Mycoplasma pneumoniae in children

BACKGROUND: The incidence of necrotizing pneumonia (NP) caused by Mycoplasma pneumoniae (MP) is increasing. We analyzed the clinical characteristics and the risk factors for NP caused by MP. METHODS: A retrospective observational study was conducted in 37 patients with NP caused by MP (NP group) and 74 patients diagnosed with lobar M. pneumoniae pneumonia with no necrosis (control group) who were admitted to our hospital between January 2013 and December 2017. The clinical manifestations, laboratory data, imaging findings, treatments and outcomes were analyzed. RESULTS: The proportion of females, the incidence of pleural effusion, fever duration, hospitalization days, white blood cell count, neutrophil ratio, D-dimer level and use of other types of antibiotics were higher in the NP group than in the control group (P < 0.05). The control group exhibited a greater use of low molecular weight heparin (LMWH) than the NP group (P < 0.05). According to the multivariate logistic regression analysis, a white blood cell count > 12.3 × 10(9)/L (Odds ratio, OR = 6.412), a neutrophil ratio > 73.9% (OR = 6.081) and D-dimer level > 1367.5 ng/mL (OR = 8.501) were risk factors for pulmonary necrosis caused by MP. Furthermore, the use of LMWH (OR = 0.074) reduced the risk of pulmonary necrosis. CONCLUSIONS: NP is a rare complication of severe Mycoplasma pneumoniae pneumonia (SMPP), and although the clinical course is longer than common MP infection, the necrotic area is absorbed gradually. In patients with SMPP presenting with lobar consolidation, a white blood cell count > 12.3 × 10(9)/L, a neutrophil ratio > 73.9% and D-dimer level > 1367.5 ng/mL are risk factors for pulmonary necrosis, and the use of LMWH reduces the risk of pulmonary necrosis.