The role of Mycoplasma pneumoniae in acute exacerbation of asthma in children.

Background: The aim of this retrospective study was to test the connection between acute M. pneumoniae infection and the exacerbation of asthma. The clinical characteristics of Mycoplasma infection seen during emergent visits in asthmatic children were reviewed.

Methods: We examined the cases of 316 asthma exacerbation patients aged from two to fourteen-years-old. They were divided into two groups according to their asthma history. One hundred and eighty-eight cases had evidence of a history of asthma (group 1) and 128 had only had their first asthma attack (group 2). The control group (group 3) was made up of 151 asthmatic children who had no acute exacerbation during the previous six months. In all three groups, we looked whether those children had acute M. pneumoniae infection or not. Acute M. pneumoniae infection was defined by positive results in serologic testing, with specific immunoglobulin M (IgM) antibody or with a > or = fourfold increase in IgG titer by the third week in the same children.

Results: In group 1, acute M. pneumionae infection was found in 42 (23%) of the 188 children. In group 2, acute M. pneumoniae infection was proven in 57 (45%) of the 128 children. In the control group, 10 (7%) of the 151 children had M. pneumoniae infection. Twenty-three (54%) asthmatic children that presented with fever as the chief complaint were infected with M. pneumoniae, compared with 18 (12%) children without infection (p = 0.014). Twenty-nine (50%) children having their first asthma attack with fever were infected with M. pneumoniae, compared with 22 (32%) without infection (p = 0.009). In group 1, 17 (41%) children with M. pneumoniae infections and 28 (19%) children without M. pneumoniae infections presented with rale breathing sounds of the physical examination (p = 0.027). In group 2, 26 (46%) children with M. pneumoniae infections and 17 (24%) children without M. pneumoniae infections presented with rale breathing sounds (p = 0.019).

Conclusions: We found that M. pneumoniae may play a role in asthmatic exacerbation among children, especially in those experiencing their first asthma attack. Moreover, among children with acute M. pneumoniae infection, the number was significantly increased of children having fever as the chief complaint and rales in auscultations compared with those without M. pneumoniae infection.