A Case of Hypoxemic Acute Bronchiolitis Presenting with Diffuse Nodular Shadows Caused by Mycoplasma pneumoniae

A fifty year-old female who had previously been well presented with a productive cough and a high fever. Her initial chest X-ray film showed no abnormal lung shadows. Despite partial improvment of the fevere and the serum level of acute phase reactant (CRP) in response to intravenous administration of piperacillin, she complained of increasing severity of cough and dyspnea. Follow-up chest X-ray films taken five days after therapy with piperacillin showed diffuse nodular shadows in the mid-to-lower lung fields bilaterally. Chest CT scan disclosed diffuse miliary nodules at the lung periphery and thickenning of bronchovascular markings. Chest auscultation revealed late inspiratory coarse crackles and expiratory wheezing, and the patient's arterial oxygen tension was 61mmHg. Suspected of suffering from primary atypical pneumonia, she was started on therapy with intravenous minocyclin (200mg/day), two days after treatment her symptoms began improving significantly. Anti-mycoplasma antibody was found to be×280, and cold hemoagglutini×1024, establishing the diagnosis of Mycoplasma pneumoniae infection. The patient's condition completely recovered following a one week treatment with minocyclin. We concluded that her respiratory infection was caused by piperacillin-sensitive mico-organism, and also Mycoplasma pneumoniae which brought about hypoxic acute bronchiolitis to the patient.