The Incidence and Risk Factors of Extrapulmonary Manifestations in mycoplasma Pneumoniae Pneumonia

Background: Mycoplasma pneumoniae pneumonia (MP) is a major cause of community acquired pneumonia (CAP) in children and it is known to be associated with extrapulmonary manifestations (EPM). The incidence and risk factors of EPM in children are not known.Methods: This is a retrospective study involving 65,243 pediatric CAP patients between 2010 and 2015 at 23 nationwide hospitals was conducted in South Korea. The medical records were reviewed to collect the information regarding the clinical characteristics, radiological results, and laboratory findings. In total, 9,190 children with MP were identified and included in the analysis. Logistic regression with multivariable analysis was performed to evaluate the risk factors associated with EPM in MP.Results: The mean age of the enrolled patients with MP was 64.3±39.8 months, and the proportion of male patients was 49.5%. The incidence of EPM was 23.9% and included elevation of liver enzymes (18.1%), mucocutaneous manifestations (4.4%), proteinuria (4.1%), cardiovascular and neurologic manifestation (0.4%), hematologic manifestation (0.2%) and arthritis (0.2%). Statistical analysis showed that mucocutaneous manifestations were significantly increased with elevated alanine aminotransferase (adjusted odds ratio [aOR] 3.623, 95% confidence intervals [CI] 1.933-6.790) and atopic sensitization (aOR 2.973, 95% CI 1.615-5.475) and decreased with respiratory virus co-infection (aOR 0.273, 95% CI 0.084-0.887). Elevated liver enzymes was significantly associated with the elevation of lactate dehydrogenase (aOR 3.055, 95% CI 2.257-4.137) and presence of pleural effusion (aOR 2.635, 95% CI 1.767-3.930) and proteinuria with respiratory virus co-infection (aOR 2.245, 95% CI 1.113-4.527). Conclusions: About 24% of pediatric MP patients were identified with various EPM. Since risk factors associated with each EPM was different, it is necessary to evaluate the various clinical aspects and findings of MP to predict and prepare for the occurrence of EPM.