RESUMO
A case of Mycoplasma pneumoniae bronchiolitis with hypoxemia is presented. A 41-year-old man was admitted to hospital because of fever, productive cough and dyspnea with wheezing of one month duration. On admission, bronchial asthma was suspected on the basis of reversible airflow obstruction and sputum eosinophilia. However, despite treatment with bronchodilators, his condition did not improve. Chest film and computed tomogram revealed small nodular shadows and tramlines in the bilateral lower lung fields, and pulmonary function tests indicated peripheral airway obstruction. Serologic titer for Mycoplasma pneumoniae was 1:160. A diagnosis of bronchiolitis due to Mycoplasma pneumoniae was made. Improvement of lung function and roentgenographic findings was observed following administration of erythromycin and doxycycline. The concentrations of prostanoids in sputum were markedly higher than in cases of bronchial asthma, and decreased as he improved. These observations suggest that Mycoplasma bronchiolitis should be considered in the differential diagnosis of wheezing, and that measurement of prostanoids in sputum may be useful in the differentiation of infective bronchiolitis and bronchial asthma.