We investigated the clinical manifestations, radiographic and laboratory findings of children with M. pneumoniae pneumonia(MP) according to their age.

A total of 75 children with MP who admitted to The Catholic University, Daejeon St. Mary's Hospital from July 2003 to February 2004, were classified into the three age groups : the ≤2 years of age(16 children), the children between 3 and 5 years of age(35 children), and the ≥6 years and older(24 patients). The diagnosis of MP was depended on the titers of anti-mycoplasma antibody that were measured 2 times, at admission and at discharge.

The total duration of the fever and the length of hospitalization were not different among the age groups. Although the white blood cell(WBC) value and differential was significantly different between the groups(P<0.01), a similar number in the WBC and reduced lymphocyte proportion was observed in all age groups compared to age-matched references. The patterns of pneumonia were significantly different according to age, i.e. segmental or lobar patterns were observed in 5 cases(31.3%) in the ≤2 years old group, but 16 cases(66.6%) in the >6 years old group(P<0.01).

Although there was no difference in clinical findings according to age in MP, the radiographic finding was more severe in older children.