Severe asthma exacerbation: role of acute Chlamydophila pneumoniae and Mycoplasma pneumoniae infection

BACKGROUND Chlamydophila pneumoniae and Mycoplasma pneumoniae are associated with acute exacerbation of bronchial asthma (AEBA). The aim of this study was to evaluate the correlation between these acute bacterial infections and the severity of AEBA. METHODS We prospectively analysed consecutive patients admitted to the Emergency Department with acute asthma exacerbation. In every patient peak expiratory flow (PEF) measurement was performed on admission, and spirometry during follow-up. Serology for Chlamydophila and Mycoplasma pneumoniae was performed on admission and after 4-8 weeks. RESULTS Fifty-eight patients completed the study. Acute atypical infections (AAI) was observed in 22/58 cases; we found single acute C. pneumoniae in 19 cases, single acute M. pneumoniae in 2 cases, and double acute infection in one case. Functional impairment on admission was greater in patients with AAI than in patients without AAI (PEF 205 +/- 104 L/min vs 276 +/- 117 p = 0.02) and persisted until visit 2 (FEV1% 76.30 +/- 24.54 vs FEV1% 92.91 +/- 13.89, p = 0.002). Moreover, the proportion of patients who presented with severe AEBA was significantly greater in the group with AAI than in the group without AAI (15/22 vs 12/36, p = 0.01; OR 4.29, 95% CI 1.38-13.32). CONCLUSION Our data suggest an association between acute atypical infection and a more severe AEBA.