Application Value of Lung Ultrasound in Children With Macrolide‐Unresponsive <scp> <i>Mycoplasma pneumoniae</i> </scp> Pneumonia

OBJECTIVE: The incidence of macrolide-unresponsive Mycoplasma pneumoniae pneumonia (MUMPP) has markedly increased, primarily owing to resistance mediated by mutations in the pathogen's 23S rRNA gene. Because macrolide susceptibility testing is impractical at admission, this study aimed to delineate the clinical characteristics of MUMPP in children and to evaluate the predictive utility of laboratory parameters and lung ultrasound features for identifying MUMPP. METHODS: A retrospective analysis was performed on 163 children hospitalized with Mycoplasma pneumoniae pneumonia (MPP) at the Department of Pediatrics, Ordos Central Hospital, from January 1, 2023, to December 31, 2024. Patients were stratified into the MUMPP group (n = 49) and the macrolide-sensitive Mycoplasma pneumoniae pneumonia (MSMP) group (n = 114) according to their response to macrolide antibiotics. RESULTS: Compared with the MSMP group, patients in the MUMPP group were older, had longer hospital stays, and had higher body temperatures. d-dimer levels and neutrophil-to-lymphocyte ratios (NLRs) were elevated in the MUMPP group. On lung ultrasound, the MUMPP group exhibited larger areas of lung consolidation at admission and after treatment, higher rates of pleural effusion, greater bilateral pulmonary involvement, and a higher proportion of consolidations without air bronchograms. CONCLUSION: Children with MUMPP present with more severe clinical features and lung ultrasound manifestations than those with MSMP. Early initiation of non-macrolide alternative therapies is therefore critical for effective management of MUMPP.