changes of airway reactivity after mycoplasma pneumoniae infection in children: a study for early precautions against pediatric asthma

the relationship between mycoplasma pneumoniae (mp) infection and asthma has rarely been explored through examination of airway reactivity. the aim of this study was to determine airway reactivity changes after mp infection in children. first, 106 children were divided into four groups according to the existence of mp infection and/or asthma. then children with only mp belonged to the mp group; children who had both mp infection and asthma belonged to the mp+a group; children with asthma but not mp infection belonged to the non-mp +a group; normal children were classified as normal control (nc) group. each subject underwent a bronchial provocation test (bpt) after effectively controlling the symptoms. airway hyperresponsiveness (ahr) parameters were compared among the groups. bpt positive rates were also calculated and compared. all ahr parameters decreased following mp infection, with a more significant decrease of small airway reactivity related indexes. the bpt-positive rate in the mp +a group was significantly higher than that in the mp group. large airway reactivity showed no significant differences between the mp+a and non-mp+a groups, while the small airway reactivity   augmented more significantly in the mp +a group. mp infection caused increased reactivity of both large and small airways in lungs, and bpt-positive identification in some patients.