A 39-year-old Taiwanese male painter had a history of alcohol consumption (approximately 90 units of alcohol per week for more than 6 years) and smoking (30 pack-years), but no illicit drugs use. Initially, he was brought to our hospital on 31 August 2018 with hemoptysis, yellowish thick sputum, a retrosternal burning sensation, and a 2-month history of progressive cough. No fever, chest pain, dyspnea, or tarry stool was found. He denied any previous medical history and he also denied previous travel history. At the emergency department, physical examination revealed a heart rate of 102 beats per minute, blood pressure of 133/82 mm Hg, respiratory rate of 20 breaths per minute, oxygen saturation of 89% on room air, and temperature of 37.0  Celsius. There was no lymphadenopathy or splenomegaly. There were left lower lung crackles on chest auscultation, and the neurological examination was normal. A chest radiograph showed a cavitary lesion in the left lower lung area (Fig. 1A). Chest high-resolution computed tomography revealed a cavitary mass with air-fluid level over the left upper and lower lobes (Fig. 1E); therefore, lung abscess was diagnosed. For community acquired pneumonia, these are many types of pathogens which could induce pneumonia with parenchymal cavitary lesion, including Gram negative bacteria such as Klebsiella pneumoniae and Haemophilus influenzae, Gram positive bacteria such as Staphylococcus aureus including methicillin-resistant Staphylococcus aureus (MRSA) and Streptococcus pneumoniae, atypical bacteria such Mycoplasma pneumoniae and Legionella pneumophila, pulmonary tuberculosis, fungal infection, and parasite infection. The patient was admitted to our ward on 31 August 2018. The initial white blood cell (WBC) count was 10.33 x 1000/muL, C-reactive protein was 97.8 mg/L, and eosinophilic percentage was about 0.8%. Based on the laboratory data, bacterial infection was suspected. In addition, due to previous alcoholism history, Gram negative bacterial infection was highly suspected, especially Klebsiella pneumoniae. According to 2019 American Thoracic Society (ATS) and Infectious Diseases Society of America (IDSA) for pneumonia treatment guide suggestion, beta-lactam with fluoroquinolone combination therapy is considered as a standard regimen for severe inpatient pneumonia. In our patient, the chest CT revealed lung abscess lesion over the left upper and lower lobes. Lung abscess is a relatively more severe pattern of pneumonia. In addition, the patient had used to drink alcohol for a long time, and immunocompromised status should be considered. According to ATS & IDSA guideline, combined treatment with Curam (amoxycillin + clavulanate potassium) and levofloxacin should be suitable in this situation.
Therefore, we prescribed intravenous amoxicillin 1000 mg/clavulanic acid 200 mg every 8 hours and levofloxacin 750 mg per day for initial treatment. The serum mycoplasma IgM titer was 0.443 OD ratio which excluded mycoplasma infection. In addition, three sets of tuberculosis acid fast stains showed negative results on 04 September 2018 afternoon, and therefore pulmonary tuberculosis infection was excluded. The sputum culture report became available on 03 September 2018, and confirmed Klebsiella pneumoniae infection, which was sensitive to all of the antibiotics except ampicillin. Besides, chest radiograph on 6 September 2018 showed persistent cavitary lesion with newly developed peripheral infiltration at left lower lung field (Fig. 1B). Therefore, we changed the antibiotics from amoxicillin/clavulanate to inhaled colimycin (colistin base 2MU (66.8 mg) = 2.0 MIU colistimethate sodium (CMS) (160 mg/vial)) every 8 hours, but we retained levofloxacin as a synergistic agent for severe pneumonia treatment. The patient's chest radiograph on 13 September 2018 showed both the cavitary lesion and peripheral infiltration at left lower lung field had improved one week after change of antibiotics (Fig. 1C), and the lung lesions were almost completely resolved after four weeks of treatment (Fig. 1D and F).