Comparing differences in onset and clinical manifestations between children and adults with Mycoplasma pneumoniae pneumonia and analyzing risk factors for severe cases, during the post-COVID-19 pandemic era.

INTRODUCTION

In the post-pandemic era, Mycoplasma pneumoniae pneumonia (MPP) has become increasingly prevalent among adults, a population previously considered less affected and poorly studied. This study aimed to compare the clinical features of MPP in children and adults and identify predictors of severe disease.

METHODOLOGY: 288 MPP patients were retrospectively analyzed. Differences in clinical classification, symptoms, imaging, laboratory markers, and treatment response were assessed between children and adults. Propensity score matching (PSM) was applied to minimize bias. Predictors of severe MPP were further analyzed.

RESULTS

Most cases were mild with predominant respiratory symptoms. After PSM, "Child" had higher thermal spike (39.01 °C vs. 38.66 °C, p = 0.017), lymphocyte percentage, and lactate dehydrogenase. "Adult" had higher C-reactive protein (CRP), erythrocyte sedimentation rate. Adults recovered significantly faster, with a higher cumulative improvement rate from day 2 (HR: 1.916, 95% CI: 1.267-2.899). Key predictors for severe MPP diverged between groups. The combination of elevated CRP, reduced lymphocyte percentage, and pre-existing diseases showed good predictive performance (AUC: 0.744) in "Child," whereas in "Adult," elevated CRP alone was the sole independent predictor (AUC: 0.749).

CONCLUSION

Cough is the dominant symptom in both groups. CRP, lymphocyte percentage, and comorbidities help assess severity in "Child". Elevated CRP alone predicts severity in "Adult". Quinolones were associated with favorable recovery in adults.