BACKGROUND: The clinical evaluation of patients with post-infectious bronchiolitis obliterans (BO) is variable. OBJECTIVE: Substantiate the clinical characteristics, the evolution and the complementary tests of 48 patients with post-infectious bronchiolitis obliterans (BO). METHOD: Observational and retrospective study. Diagnosis of BO was based upon clinical criteria, CT scan findings and exclusion of other diseases. History prior to diagnosis and complementary tests were evaluated as well as initial and final values of oxygen saturation. RESULTS: Mean age of patients at the acute stage of the infectious disease was of 9.6. Thirty two of the patients were male. All were hospitalized during the acute stage, 14 of them (29%) in the ICU. Four patients died two years after onset of acute bronchiolitis. During evolution, all required emergency care due to exacerbation of the pulmonary condition and 24 (50%) were hospitalized, 2 of them in the ICU. The majority continued presenting cough, wheezing, crackles and hyperinflation, however to a lesser degree. Mean of initial arterial saturation was of 89% and final of 92%. The most common infectious agents in sputum samples were H. influenzae, S. pneumoniae and M. catarrhalis. Increased serum IgM and IgC were found in 9 and 7 patients, respectively. The most frequent findings at thorax CT scan were mosaic perfusion, bronchiectasis, atelectasis and bronchial wall thickening. CONCLUSION: Post infectious BO is a chronic and severe disease with persistent symptoms that in general affect infants. Positive serum cultures and increased serum immunoglobulins are suggestive of chronic infectious inflammatory condition.

Keywords: Bronchiolitis obliterans. Obstructive lung diseases.