Abstract
OBJECTIVE: Mycoplasma pneumoniae pneumonia (MPP) in children is a common respiratory infection, with rising concerns over macrolide-resistant strains. The aim of this study is to establish an effective diagnostic prediction model for refractory MPP (RMPP) and evaluate doxycycline as an alternative treatment for macrolide-unresponsive MPP (MUMPP). METHODS: 106 children with RMPP receiving doxycycline and 73 children with MUMPP treated with azithromycin were retrospectively analyzed. For all patients, the detection of MP-DNA in BALF, alongside clinical criteria, served to confirm active MP infection and infer phenotypic macrolide unresponsiveness/resistance. Univariate and multivariate logistic regression analyses were then used to identify clinically available risk factors for the development of RMPP among these patients with MP pneumonia. RESULTS: The doxycycline group had significantly shorter fever duration, fewer lavage procedures, reduced steroid use, and shorter hospital stays compared to the azithromycin group (P < 0.05). Multivariate analysis identified four independent risk factors for RMPP: duration of macrolide use before admission, days of fever before hospitalization, procalcitonin (PCT), and C-reactive protein (CRP). A nomogram based on these factors showed excellent discrimination, with an AUC of 0.982 (95% CI: 0.961-1.000). The calibration curve approached the 45-degree line, and decision curve analysis (DCA) indicated that the nomogram provided positive net benefit across a reasonable range of threshold probabilities, supporting its potential clinical utility. CONCLUSION: In children with MUMPP, doxycycline treatment is associated with superior clinical outcomes compared to azithromycin. A nomogram incorporating readily available clinical factors can effectively identify patients at risk of developing RMPP, supporting early intervention.