Background

Mycoplasma pneumoniae (M. pneumoniae) infected lobar pneumonia has increased recently in children in Korea.

Objective

To evaluate the clinical and laboratory characteristics of lobar pneumonia infected by M. pneumoniae and to find more sensitive diagnostic tool in children.

Methods

We analyzed medical records of 78 children, admitted to Chungnam National University Hospital and diagnosed with lobar pneumonia by chest X-rays between March 2010 and December 2011. White blood cells, C-reactive protein (CRP), procalcitonin (PCT), specific antibodies to M. pneumoniae, and cold agglutinin (CA) were measured at admission. Children were divided into 2 groups: those with M. pneumoniae infection (group A) and those without (group B). Group A children were also subdivided into 2 categories: those with increased CA (group A1) and those without (group A2).

Results

M. pneumoniae infection usually occurred in summer and autumn. Group A children accounted for 75.6% (59/78) of all cases. The onset age was higher in group A than in group B (P=0.016). WBC counts and PCT values were higher in group B than in group A (P=0.015 and P=0.011). Radiologic findings showed that the lower lobe was most commonly involved without predilection for either side and that pleural effusion was present in 13.6% of all cases. The duration of fever before admission was longer in group A1 than in group A2 (P=0.019).

Conclusions

The clinical symptoms and signs of lobar pneumonia caused by M. pneumoniae infection were more severe and can be accurately diagnosed using serum PCT values than using CRP values.